Detection system of liquid drop generator

Abstract

The invention relates to the technical field of semiconductors, in particular to a detection system of a liquid drop generator. The detection system of the liquid drop generator comprises a vacuum tube, a pressurization mechanism, a vacuum generator, an imaging mechanism and a photoelectric measurement mechanism, wherein the top end of the vacuum tube is used for mounting the liquid drop generator to be detected. And a gas conveying pipe of the pressurizing mechanism can be communicated with a gas inlet of the liquid drop generator. The vacuum generator is configured to vacuumize the vacuum tube. The imaging mechanism is fixedly arranged outside the vacuum tube or moves in the axial direction of the vacuum tube so as to obtain images of liquid drops in the vacuum tube. The photoelectric measuring mechanism comprises a laser and a sensor, the laser and the sensor are oppositely arranged outside the vacuum tube, the laser is configured to emit laser to liquid drops in the vacuum tube in the axial direction perpendicular to the vacuum tube, and the sensor is used for receiving the laser. The droplet generator does not need to be assembled and detected on the EUV light source, so that the detection efficiency and the research and development speed of the droplet generator are improved, and the detection cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a detection system for a droplet generator. Background Art

[0002] The extreme ultraviolet lithography machine uses an extreme ultraviolet (EUV) exposure light source. The method of generating extreme ultraviolet light is to bombard a metal tin target with a high-frequency, high-energy pulsed laser to generate a high-temperature, high-density plasma. The plasma is constantly undergoing ionization and recombination processes and radiating extreme ultraviolet light. The effective element in the target that acts on the laser is metal tin, and the tin target is supplied in the form of tin droplets formed under the jet. The metal tin is heated to above its melting point to form molten liquid tin, and then the liquid tin is ejected through a micro-hole nozzle by applying air pressure to form a tin jet. At the same time, ultrasonic vibration is applied along the jet direction, and the tin jet breaks to form tin droplets with uniform spacing. Tin droplets are usually ejected vertically downward. At the same time, the laser emitted by a high-power laser is injected in a direction perpendicular to the direction of the tin jet, and after focusing, it bombards the tin droplets. The above-mentioned injected laser is a high-frequency pulsed laser, and the laser frequency needs to be synchronized with the frequency of the continuously ejected tin droplets, that is, one laser pulse acts on one tin droplet.

[0003] Existing tin droplet generators are usually installed on the vacuum chamber of the EUV light source to test parameters such as laser conversion efficiency and EUV output power, which makes the detection operation complicated and the detection efficiency low, prolonging the research and development cycle of the tin droplet generator. In addition, the EUV light source structure is too complicated and expensive, which increases the detection cost of the tin droplet generator, thereby increasing the research and development cost of the tin droplet generator. Summary of the invention

[0004] The object of the present invention is to provide a detection system for a droplet generator, so as to facilitate detection of the droplet generator, improve detection efficiency of the droplet generator, and reduce detection cost of the droplet generator.

[0005] To achieve this purpose, the technical solution adopted by the present invention is:

[0006] The detection system of the droplet generator includes:

[0007] A vacuum tube, the top of which is used to install a droplet generator to be detected;

[0008] A pressurizing mechanism, wherein the air delivery pipe of the pressurizing mechanism can be communicated with the air inlet of the droplet generator;

[0009] a vacuum generator configured to evacuate the vacuum tube;

[0010] An imaging mechanism, fixedly arranged outside the vacuum tube or moving along the axial direction of the vacuum tube to obtain an image of the droplets in the vacuum tube;

[0011] The photoelectric measuring mechanism comprises a laser and a sensor. The laser and the sensor are arranged outside the vacuum tube opposite to each other. The laser is configured to emit laser light to the droplets in the vacuum tube along an axial direction perpendicular to the vacuum tube. The sensor is used to receive the laser light.

[0012] As an optional solution of the detection system of the droplet generator, the detection system of the droplet generator also includes:

[0013] A reflux pipe, one end of which is connected to the bottom end of the vacuum pipe, and the other end of which is connected to the inlet of the droplet generator;

[0014] A pump body is installed on the reflux pipe, and the pump body is configured to pump the liquid droplets in the reflux pipe into the liquid droplet generator.

[0015] As an optional solution of the detection system of the droplet generator, the detection system of the droplet generator further includes a heater, the inlet of the heater is connected to the bottom end of the vacuum tube, and the outlet of the heater is connected to one end of the reflux tube.

[0016] As an optional solution of the detection system of the droplet generator, a first switch valve is provided at the other end of the reflux pipe connected to the inlet of the droplet generator, and the first switch valve is used to open or close the reflux pipe.

[0017] As an optional solution for the detection system of the droplet generator, the detection system of the droplet generator also includes a lifting mechanism, and the output end of the lifting mechanism is transmission-connected with the imaging mechanism to drive the imaging mechanism to be fixedly disposed outside the vacuum tube or to be lifted and moved along the axial direction of the vacuum tube.

[0018] As an optional solution of the detection system of the droplet generator, the lifting mechanism includes:

[0019] Lifting drive parts;

[0020] A lead screw, the lead screw is extended along the axial direction of the vacuum tube, and the output end of the lifting drive member is connected to the lead screw;

[0021] A carrier plate, the carrier plate is threadably matched with the lead screw, and the imaging mechanism is mounted on the carrier plate.

[0022] As an optional solution of the detection system of the droplet generator, the imaging mechanism includes:

[0023] camera;

[0024] A backlight source is arranged on the carrier board at the same height as the camera and is symmetrically arranged outside the vacuum tube.

[0025] As an optional solution of the detection system of the droplet generator, the pressurizing mechanism includes:

[0026] Gas cylinders;

[0027] An air delivery pipe, one end of which is connected to the air outlet of the gas cylinder, and the other end of which can be connected to the inlet of the droplet generator;

[0028] A second switch valve is installed on the gas pipeline to open or close the gas pipeline.

[0029] As an optional solution of the detection system of the droplet generator, the detection system of the droplet generator further includes an adapter, which is sealingly mounted on the top of the vacuum tube, and the droplet generator can be sealingly mounted on the adapter.

[0030] As an optional solution of the detection system of the droplet generator, the detection system of the droplet generator further includes a pressure gauge, which is used to measure and display the pressure in the vacuum tube.

[0031] The beneficial effects of the present invention are:

[0032] The detection system of the droplet generator proposed by the present invention includes a vacuum tube, a pressurizing mechanism, a vacuum generator, an imaging mechanism and a photoelectric measuring mechanism. The droplet generator is installed at the top of the vacuum tube. The vacuum tube maintains the air pressure environment for generating an extreme ultraviolet light source through the vacuum generator. The pressurizing mechanism is used to pressurize the droplet generator so that the droplet generator sprays droplets toward the vacuum tube. Various parameters of the droplets in the vacuum tube are obtained through the imaging mechanism and the photoelectric measuring mechanism to complete the detection of the droplet generator. There is no need to assemble and detect on the EUV light source, which simplifies the detection operation of the droplet generator, improves the detection efficiency of the droplet generator, reduces the detection cost, is conducive to improving the research and development speed of the droplet generator, and reduces the research and development cost of the droplet generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural distribution diagram of a detection system of a droplet generator provided in an embodiment of the present invention.

[0034] The names and numbers of the components in the figure are as follows:

[0035] 100. droplet generator; 101. nozzle;

[0036] 1. Vacuum tube; 2. Pressurizing mechanism; 21. Gas cylinder; 22. Gas pipe; 23. Second switch valve; 3. Vacuum generator; 4. Laser; 5. Sensor; 6. Oscilloscope; 7. Reflux pipe; 8. Pump body; 9. Heater; 10. First switch valve; 11. Camera; 12. Backlight source; 13. Adapter; 14. Pressure gauge; 15. Bellows; 16. Four-way pipe; 161. First interface; 162. Second interface; 163. Third interface; 164. Fourth interface. DETAILED DESCRIPTION

[0037] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, not all.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper", "lower", "right", "left" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0041] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0042] Existing tin droplet generators are usually installed on the vacuum chamber of the EUV light source to test parameters such as laser conversion efficiency and EUV output power, which makes the detection operation complicated and the detection efficiency low, prolonging the research and development cycle of the tin droplet generator. In addition, the EUV light source structure is too complicated and expensive, which increases the detection cost of the tin droplet generator, thereby increasing the research and development cost of the tin droplet generator.

[0043] To solve the above problems, Figure 1 As shown, this embodiment proposes a detection system for a droplet generator, which includes a vacuum tube 1, a pressurizing mechanism 2, a vacuum generator 3, an imaging mechanism and a photoelectric measuring mechanism. The top of the vacuum tube 1 is used to install the droplet generator 100 to be detected. The gas pipe 22 of the pressurizing mechanism 2 can be connected to the air inlet of the droplet generator 100. The vacuum generator 3 is configured to evacuate the vacuum tube 1. The imaging mechanism is fixedly arranged outside the vacuum tube 1 or moves along the axial direction of the vacuum tube 1 to obtain an image of the droplets in the vacuum tube 1. The photoelectric measuring mechanism includes a laser 4 and a sensor 5. The laser 4 and the sensor 5 are arranged on the outside of the vacuum tube 1 opposite to each other. The laser 4 is configured to emit laser to the droplets in the vacuum tube 1 in a direction perpendicular to the axial direction of the vacuum tube 1, and the sensor 5 is used to receive the laser. The droplet generator 100 is installed at the top of the vacuum tube 1. The vacuum tube 1 maintains the air pressure environment for generating the extreme ultraviolet light source through the vacuum generator 3. The pressurizing mechanism 2 is used to pressurize the droplet generator 100 so that the droplet generator 100 sprays droplets toward the vacuum tube 1. The various parameters of the droplets in the vacuum tube 1 are obtained through the imaging mechanism and the photoelectric measurement mechanism to complete the detection of the droplet generator 100. There is no need to assemble and detect on the EUV light source, which simplifies the detection operation of the droplet generator 100, improves the detection efficiency of the droplet generator 100, and reduces the detection cost, which is conducive to improving the research and development speed of the droplet generator 100 and reducing the research and development cost of the droplet generator 100.

[0044] In the present embodiment, the vacuum tube 1 is a round tube made of transparent materials such as quartz. In other embodiments, the material of the vacuum tube 1 can also be acrylic, silicate glass, etc., as long as it does not affect the imaging mechanism and the photoelectric measurement mechanism to obtain the various parameters of the droplets in the vacuum tube 1. The vacuum tube 1 is arranged in the vertical direction (the up and down direction in the figure) so that the droplets can be sprayed from top to bottom. The droplet generator 100 stores molten liquid tin metal, and the pressurizing mechanism 2 applies air pressure to the droplet generator 100 so that the liquid tin is sprayed through the nozzle 101 and forms a tin jet in the vacuum tube 1. At the same time, the droplet generator 100 applies ultrasonic vibration along the jet direction, so that the tin jet breaks to form tin droplets with uniform spacing.

[0045] like Figure 1 As shown, the pressurizing mechanism 2 includes a gas cylinder 21, a gas pipe 22 and a second switch valve 23, one end of the gas pipe 22 is connected to the gas outlet of the gas cylinder 21, and the other end of the gas pipe 22 can be connected to the inlet of the droplet generator 100. The second switch valve 23 is installed on the gas pipe 22 to open or close the gas pipe 22. The gas cylinder 21 stores one or more mixed gases of multiple gases such as argon, helium, neon, nitrogen, hydrogen, etc., so as to pressurize the droplet generator 100 through the gas pipe 22, so that the liquid tin metal in the droplet generator 100 is ejected from the nozzle 101. In other embodiments, a plurality of gas cylinders 21 are provided, and the plurality of gas cylinders 21 respectively store a single gas of the above-mentioned gases, and the single gas in the plurality of gas cylinders 21 is flexibly adjusted in mixing ratio according to the use requirements, and finally the mixed gas is filled into the droplet generator 100 through the gas pipe 22 to realize the pressurization operation of the droplet generator 100.

[0046] like Figure 1 As shown, the detection system of the droplet generator also includes an adapter 13, which is sealed and installed at the top of the vacuum tube 1, and the droplet generator 100 can be sealed and installed at the adapter 13. The droplet generator 100 to be detected is quickly assembled to the top of the vacuum tube 1 through the adapter 13, which improves the assembly efficiency of the droplet generator 100, thereby improving the detection efficiency of the droplet generator 100. Specifically, the adapter 13 of this embodiment is a flange joint, which is sealed and sleeved on the top of the vacuum tube 1, and the droplet generator 100 is sealed and assembled with the adapter of the flange joint, and the nozzle 101 of the droplet generator 100 passes through the flange joint and extends into the vacuum tube 1, so as to spray tin droplets to the vacuum tube 1.

[0047] Specifically, the vacuum generator 3 (i.e., vacuum pump) is used to maintain the air pressure of the vacuum tube 1 between 0.01 Pa and 100 Pa. The detection system of the droplet generator also includes a pressure gauge 14, which is used to measure and display the pressure in the vacuum tube 1. The pressure gauge 14 can accurately and real-time display the air pressure in the vacuum tube 1 to ensure the accuracy of the air pressure in the vacuum tube 1.

[0048] like Figure 1 As shown, a four-way pipe 16 is installed at the bottom end of the vacuum tube 1, and the four-way pipe 16 includes a first interface 161, a second interface 162, a third interface 163 and a fourth interface 164. Among them, the first interface 161 is connected to the bottom end of the vacuum tube 1, and the second interface is connected to the vacuum generator 3 through the bellows 15, so that the vacuum generator 3 can evacuate the vacuum tube 1 through the bellows 15 and the four-way pipe 16. A pressure gauge 14 is installed on the third interface so that the pressure gauge 14 can accurately measure the air pressure value in the vacuum tube 1.

[0049] It should be noted that the detection system of the droplet generator also includes a lifting mechanism (not shown in the figure), the output end of the lifting mechanism is connected to the imaging mechanism in a transmission manner to drive the imaging mechanism to be fixedly arranged outside the vacuum tube 1 or to move up and down along the axial direction of the vacuum tube 1. When the imaging mechanism is fixedly arranged outside the vacuum tube 1, the imaging mechanism continuously shoots at a fixed position to achieve high-speed imaging of the droplets, thereby obtaining an image of the droplets; when the lifting component drives the imaging mechanism to move up and down along the axial direction of the vacuum tube 1, the droplets in the vacuum tube 1 are scanned and photographed to achieve high-speed imaging of the droplets, thereby obtaining an image of the droplets.

[0050] Specifically, the lifting mechanism includes a lifting drive, a lead screw and a carrier plate. The lead screw is arranged to extend along the axial direction of the vacuum tube 1, and the output end of the lifting drive is connected to the lead screw. The carrier plate is threadedly matched with the lead screw, and the imaging mechanism is installed on the carrier plate. The lifting drive of this embodiment is a motor, which has the advantages of simple structure and high control accuracy. The threaded match between the lead screw and the carrier plate improves the movement accuracy and stability of the imaging mechanism.

[0051] In this embodiment, the imaging mechanism includes a camera 11 and a backlight source 12. The backlight source 12 is arranged on the carrier at the same height as the camera 11, and the camera 11 and the backlight source 12 are symmetrically arranged outside the vacuum tube 1. The camera 11 is a high-speed camera (i.e., a digital industrial camera), which converts the target into an image signal through a digital image acquisition and transmits it to a dedicated image processing system. High-speed cameras have the advantages of high image stability, high transmission capacity, and high anti-interference ability. By taking images of droplets with a high-speed camera, the shooting accuracy is improved, which is conducive to improving the detection accuracy of the droplet generator 100. The backlight source 12 is kept at the same height as the camera 11, so that the backlight source 12 provides backlight to the camera 11, further improving the clarity of the image.

[0052] It should be noted that the images captured by the camera 11 are mainly the emission morphology and geometric parameters of the droplets. The image processing system inside or outside the imaging mechanism can obtain parameter information such as the temperature, diameter, volume, shape, circumference, contour, color and surface morphology of the droplets through the images captured by the camera 11. Since the image processing system is a prior art, the working process of the image processing system will not be described in detail.

[0053] Furthermore, the photoelectric measuring mechanism also includes an oscilloscope 6, which is electrically connected to the sensor 5 to receive the laser signal received by the sensor 5. The oscilloscope 6 can display information such as the intensity of the laser signal received by the sensor 5, and obtain parameter information such as the velocity, velocity vector, reflectivity and emissivity of the droplet according to the received laser signal. In addition, according to different detection requirements, the sensor 5 can include a photodiode, a pyrometer, an infrared detector, a visible light detector, an ultraviolet light detector, an infrared camera, a visible light camera, an ultraviolet camera, an X-ray sensor, an ultrasonic sensor or a mechanical force sensor, etc. Since the above-mentioned sensors 5 are all existing technologies, and the above-mentioned photoelectric measuring mechanism is a conventional measuring mechanism required in the detection operation of the droplet generator 100, the specific composition and detection process of the photoelectric measuring mechanism will not be described in detail.

[0054] like Figure 1 As shown, the detection system of the droplet generator also includes a reflux pipe 7 and a pump body 8, one end of the reflux pipe 7 is connected to the bottom end of the vacuum tube 1, and the other end of the reflux pipe 7 is connected to the inlet of the droplet generator 100. The pump body 8 is installed on the reflux pipe 7, and the pump body 8 is configured to pump the droplets in the reflux pipe 7 into the droplet generator 100. The droplets falling on the bottom of the vacuum tube 1 enter the reflux pipe 7 and flow back to the droplet generator 100 under the drive of the pump body 8 to achieve circulation detection. The above-mentioned pump body 8 is an electromagnetic pump.

[0055] Furthermore, the detection system of the droplet generator also includes a heater 9, the inlet of the heater 9 is connected to the bottom end of the vacuum tube 1, and the outlet of the heater 9 is connected to one end of the reflux pipe 7. Specifically, the fourth interface 164 of the four-way pipe 16 is connected to the inlet of the heater 9. The droplets in the vacuum tube 1 enter the heater 9 for heating to increase the temperature of the droplets to prevent the droplets from solidifying into a solid state and blocking the reflux pipe 7 after the temperature of the droplets in the vacuum tube 1 drops. The heating temperature of the heater 9 can be flexibly set, as long as it is ensured that the droplets do not solidify into a solid state.

[0056] like Figure 1 As shown, the other end of the reflux pipe 7 connected to the inlet of the droplet generator 100 is provided with a first switch valve 10, and the first switch valve 10 is used to open or close the reflux pipe 7. By opening the first switch valve 10, the reflux pipe 7 is opened, so that the droplets flow back from the reflux pipe 7 to the droplet generator 100.

[0057] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A detection system for a droplet generator, characterized in that: include: A vacuum tube (1), the top end of the vacuum tube (1) being used to install a droplet generator (100) to be detected; A pressurizing mechanism (2), wherein the air delivery pipe (22) of the pressurizing mechanism (2) is capable of being in communication with the air inlet of the droplet generator (100); a vacuum generator (3), the vacuum generator (3) being configured to evacuate the vacuum tube (1); An imaging mechanism, fixedly arranged outside the vacuum tube (1) or movable along the axial direction of the vacuum tube (1) to obtain an image of a droplet in the vacuum tube (1); A photoelectric measurement mechanism, the photoelectric measurement mechanism comprising a laser (4) and a sensor (5), the laser (4) and the sensor (5) being arranged outside the vacuum tube (1) opposite to each other, the laser (4) being configured to emit laser light to a liquid droplet in the vacuum tube (1) along an axial direction perpendicular to the vacuum tube (1), and the sensor (5) being used to receive the laser light.

2. The detection system of the droplet generator according to claim 1, characterized in that: The detection system of the droplet generator also includes: A reflux pipe (7), one end of which is connected to the bottom end of the vacuum pipe (1), and the other end of which is connected to the inlet of the droplet generator (100); A pump body (8) is installed on the reflux pipe (7), and the pump body (8) is configured to pump the liquid droplets in the reflux pipe (7) into the liquid droplet generator (100).

3. The detection system of the droplet generator according to claim 2, characterized in that: The detection system of the droplet generator further comprises a heater (9), the inlet of the heater (9) being connected to the bottom end of the vacuum tube (1), and the outlet of the heater (9) being connected to one end of the reflux tube (7).

4. The detection system of the droplet generator according to claim 3, characterized in that: The other end of the reflux pipe (7) connected to the inlet of the droplet generator (100) is provided with a first switch valve (10), and the first switch valve (10) is used to open or close the reflux pipe (7).

5. The detection system of the droplet generator according to claim 1, characterized in that: The detection system of the droplet generator further comprises a lifting mechanism, the output end of which is in transmission connection with the imaging mechanism, so as to drive the imaging mechanism to be fixedly arranged outside the vacuum tube (1) or to move up and down along the axial direction of the vacuum tube (1).

6. The detection system of the droplet generator according to claim 5, characterized in that: The lifting mechanism comprises: Lifting drive parts; A lead screw, the lead screw being arranged to extend along the axial direction of the vacuum tube (1), and the output end of the lifting drive member being connected to the lead screw; A carrier plate, the carrier plate is threadably matched with the lead screw, and the imaging mechanism is mounted on the carrier plate.

7. The detection system of the droplet generator according to claim 6, characterized in that: The imaging mechanism comprises: Camera (11); A backlight source (12), the backlight source (12) being arranged on the carrier board at the same height as the camera (11), and symmetrically arranged outside the vacuum tube (1).

8. The detection system for a droplet generator according to any one of claims 1 to 7, characterized in that: The pressurizing mechanism (2) comprises: Gas cylinder (21); an air delivery pipe (22), one end of the air delivery pipe (22) being connected to the air outlet of the gas cylinder (21), and the other end of the air delivery pipe (22) being connectable to the inlet of the droplet generator (100); A second switch valve (23), the second switch valve (23) is installed on the gas pipeline (22) to open or close the gas pipeline (22).

9. The detection system for a droplet generator according to any one of claims 1 to 7, characterized in that: The detection system of the droplet generator further comprises an adapter (13), wherein the adapter (13) is sealingly mounted on the top end of the vacuum tube (1), and the droplet generator (100) can be sealingly mounted on the adapter (13).

10. The detection system for a droplet generator according to any one of claims 1 to 7, characterized in that: The detection system of the droplet generator also includes a pressure gauge (14), and the pressure gauge (14) is used to measure and display the pressure in the vacuum tube (1).

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