Device and method for generating metal liquid drops

Abstract

The invention belongs to the technical field of extreme ultraviolet light source generation, and discloses a metal liquid drop generation device and method. The generating device comprises a containing assembly, a first gas cylinder, a liquid drop generating assembly, a first pipeline and a second pipeline. The containing assembly is provided with a cavity, the solid metal can be contained in the cavity, the containing assembly can be heated to heat and melt the solid metal into liquid metal, the first gas cylinder communicates with the cavity of the containing assembly through a first pipeline, and the first gas cylinder can pump gas into the containing assembly; the liquid drop generation assembly communicates with the cavity of the containing assembly through a second pipeline, the second pipeline and the liquid drop generation assembly can both be heated, and the liquid drop generation assembly can emit metal liquid drops. The first gas cylinder pumps air or oxygen into the cavity of the containing assembly, the containing assembly, the second pipeline and the liquid drop generation assembly are heated, so that compact oxide layers are formed on the inner walls of the containing assembly, the second pipeline and the liquid drop generation assembly, liquid metal is prevented from flowing and dissolving the three, the service life of the generation device is prolonged, and the stability of the generation device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of extreme ultraviolet light source generation, and in particular to a device and method for generating metal droplets. Background Art

[0002] In recent years, as lithography technology has developed rapidly towards more sophisticated manufacturing, semiconductor production processes have been able to produce semiconductor devices with increasingly fine feature sizes. Among them, extreme ultraviolet lithography technology can achieve higher resolution, produce finer line widths and smaller transistor sizes, making extreme ultraviolet lithography irreplaceable in the manufacture of advanced process chips.

[0003] At present, lasers are usually used to generate plasma, and high-energy pulsed lasers are bombarded on tin droplets to form the required plasma to radiate extreme ultraviolet light. Usually, tin needs to be heated to more than 231.9℃ to become liquid metal. If the heating rate is too fast, the alloy elements in the pipeline of the generator will dissolve, and if the cooling rate is too fast, the local tin in the generator will solidify.

[0004] Therefore, it is necessary to provide a device and method for generating metal droplets to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a device and method for generating metal droplets, wherein at least part of the inner wall of the generating device can form a dense oxide layer to prevent the liquid metal from flowing and dissolving the generating device, thereby improving the service life and stability of the generating device.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A device for generating metal droplets, comprising:

[0008] A containing component having a cavity, in which solid metal can be contained, and the containing component can be heated to melt the solid metal into liquid metal;

[0009] A first gas cylinder is connected to the cavity of the containing assembly through a first pipeline, and the first gas cylinder can pump gas into the containing assembly;

[0010] The droplet generating component is connected to the cavity of the containing component through a second pipe. Both the second pipe and the droplet generating component can be heated, and the droplet generating component can emit metal droplets.

[0011] Preferably, the accommodation component comprises:

[0012] A holding tank, wherein the holding tank has the cavity;

[0013] The first heating element is arranged on the outer periphery of the containing tank, and the first heating element is used to heat the containing tank.

[0014] Preferably, the droplet generating assembly comprises:

[0015] a droplet generator, connected to the cavity of the containing component through the second pipe;

[0016] The second gas cylinder is connected to the liquid droplet generator through a third pipeline, and the second gas cylinder can pump gas into the liquid droplet generator so that the liquid droplet generator emits the metal droplets.

[0017] Preferably, the metal droplet generating device further comprises:

[0018] A recovery container, into which the metal droplets can be sprayed, and the recovery container is connected to the containing component through a fourth pipe.

[0019] Preferably, the metal droplet generating device further comprises:

[0020] A vacuum component is provided with a vacuum chamber, wherein at least a portion of the droplet generating component and the recovery container are located in the vacuum chamber.

[0021] Preferably, the vacuum assembly comprises:

[0022] A vacuum member having the vacuum chamber;

[0023] A vacuum pump is connected to the vacuum component, and the vacuum pump is used to evacuate the vacuum component.

[0024] Preferably, the metal droplet generating device further comprises:

[0025] A thermometer is used to detect the temperature in the cavity of the containing component.

[0026] Preferably, the metal droplet generating device further comprises:

[0027] A barometer is used to detect the air pressure in the cavity of the containing component.

[0028] A method for generating metal droplets, based on the above-mentioned device for generating metal droplets, the method for generating metal droplets comprises the following steps:

[0029] S1. The first gas cylinder pumps air or oxygen into the containing assembly;

[0030] S2, the containing component, the second pipe and the droplet generating component are heated to a first preset temperature and maintained for a preset time;

[0031] S3, adding the solid metal into the containing component, and heating the containing component to a second preset temperature to melt the solid metal into the liquid metal;

[0032] S4, detecting whether the oxygen concentration in the containing component and the droplet generating component is the target oxygen concentration, if so, proceeding to step S5, if not, pumping inert gas into the containing component and the droplet generating component by the first gas cylinder;

[0033] S5, the containing component, the second pipe and the droplet generating component are heated to a third preset temperature;

[0034] S6. The first gas cylinder pumps an inert gas into the containing component to make the liquid metal flow to the droplet generating component, and the droplet generating component emits the metal droplets.

[0035] Preferably, in step S2, the first preset temperature is 200°C-500°C, and the preset time is 24h-48h.

[0036] Beneficial effects of the present invention:

[0037] The generating device comprises a containing component, a first gas cylinder, a droplet generating component, a first pipe and a second pipe. The containing component has a cavity, solid metal can be contained in the cavity, the containing component can be heated to melt the solid metal into liquid metal, the first gas cylinder is connected to the cavity of the containing component through the first pipe, the first gas cylinder can pump gas into the containing component, the droplet generating component is connected to the cavity of the containing component through the second pipe, the second pipe and the droplet generating component can both be heated, and the droplet generating component can emit metal droplets.

[0038] Before melting solid metal into liquid metal, first use the first gas cylinder to pump air or oxygen into the cavity of the containing component. Since the droplet generating component is connected to the cavity of the containing component through the second pipe, air or oxygen can be pumped into the containing component, the second pipe and the droplet generating component, that is, the oxygen content inside the three is relatively high. Then, the containing component, the second pipeline and the droplet generating component are heated to form a dense oxide layer on the inner walls of the containing component, the second pipeline and the droplet generating component, so as to prevent the subsequent liquid metal from dissolving the three when flowing in the containing component, the second pipeline and the droplet generating component, thereby improving the service life and stability of the generating device; after the solid metal is melted into liquid metal, the first gas cylinder can pump gas into the cavity of the containing component to drive the liquid metal in the cavity to flow into the droplet generating component, and the droplet generating component can emit the liquid metal to form metal droplets; after the metal droplet emission is completed, the containing component, the second pipeline and the droplet generating component can be slowly cooled to prevent the local liquid metal in the generating device from solidifying due to the cooling rate being too fast, thereby avoiding the problem of blockage of the generating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of a device for generating metal droplets provided by the present invention;

[0040] Figure 2 It is a flow chart of the method for generating metal droplets provided by the present invention.

[0041] In the figure:

[0042] 1. containing assembly; 11. containing tank; 111. cavity; 12. first heating element;

[0043] 2. First gas cylinder;

[0044] 31. First pipeline; 32. Second pipeline; 33. Third pipeline; 34. Fourth pipeline;

[0045] 4. droplet generating assembly; 41. droplet generator; 42. second gas cylinder;

[0046] 5. Recycling containers;

[0047] 6. vacuum assembly; 61. vacuum part; 611. vacuum chamber; 62. vacuum pump;

[0048] 7. Thermometer;

[0049] 8. Barometer. DETAILED DESCRIPTION

[0050] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be 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 ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0051] 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.

[0052] 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.

[0053] In the description of this embodiment, the terms "upper", "lower", "right", etc., 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 operated 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.

[0054] At present, lasers are usually used to generate plasma, and high-energy pulsed lasers are bombarded on tin droplets to form the required plasma to radiate extreme ultraviolet light. Usually, tin needs to be heated to more than 231.9℃ to become liquid metal. If the heating rate is too fast, the alloy elements in the pipeline of the generator will dissolve, and if the cooling rate is too fast, the local tin in the generator will solidify.

[0055] To solve the above problems, Figure 1As shown, this embodiment provides a device for generating metal droplets, which includes a containing component 1, a first gas cylinder 2, a droplet generating component 4, a first pipe 31 and a second pipe 32. The containing component 1 has a cavity 111, solid metal can be contained in the cavity 111, the containing component 1 can be heated to heat and melt the solid metal into liquid metal, the first gas cylinder 2 is connected to the cavity 111 of the containing component 1 through the first pipe 31, the first gas cylinder 2 can pump gas into the containing component 1, the droplet generating component 4 is connected to the cavity 111 of the containing component 1 through the second pipe 32, the second pipe 32 and the droplet generating component 4 can both be heated, and the droplet generating component 4 can emit metal droplets.

[0056] Before melting the solid metal into liquid metal, first use the first gas cylinder 2 to pump air or oxygen into the cavity 111 of the containing component 1. Since the droplet generating component 4 is connected to the cavity 111 of the containing component 1 through the second pipe 32, air or oxygen can be pumped into the containing component 1, the second pipe 32 and the droplet generating component 4, that is, the oxygen content inside the three is relatively high. Then, the containing component 1, the second pipe 32 and the droplet generating component 4 are heated so that a dense oxide layer is formed on the inner walls of the containing component 1, the second pipe 32 and the droplet generating component 4 to prevent the subsequent liquid metal from dissolving the three when flowing in the containing component 1, the second pipe 32 and the droplet generating component 4, thereby improving the service life and stability of the generating device; after the solid metal is melted into liquid metal, the first gas cylinder 2 can pump gas into the cavity 111 of the containing component 1 to drive the liquid metal in the cavity 111 to flow into the droplet generating component 4, and the droplet generating component 4 can emit the liquid metal to form metal droplets; after the metal droplet emission is completed, the containing component 1, the second pipe 32 and the droplet generating component 4 can slowly cool down to prevent the local liquid metal in the generating device from solidifying due to the cooling rate being too fast, thereby avoiding the problem of blockage of the generating device.

[0057] In this embodiment, the metal is tin. It should be noted that the metal may also be xenon, lithium, etc. The specific type of the metal depends on actual needs and is not limited in this embodiment.

[0058] Specifically, Figure 1 As shown, the containing assembly 1 includes a containing tank 11 and a first heating element 12. The containing tank 11 has the above-mentioned cavity 111. The first heating element 12 is arranged at the periphery of the containing tank 11, and the first heating element 12 is used to heat the containing tank 11. The first heating element 12 is arranged at the periphery of the containing tank 11, which can ensure that the containing tank 11 is evenly heated, and helps the solid metal to melt evenly in the cavity 111, avoiding the problem of local overheating or uneven melting; the external first heating element 12 is easier to maintain or repair, and can be easily disassembled or replaced without affecting the structure of the containing tank 11 itself.

[0059] In this embodiment, the first heating element 12 is a resistance wire; in other embodiments, the first heating element 12 is a heater. It should be noted that any structure in the prior art that can heat the holding tank 11 can be used as the first heating element 12 in this embodiment, and this embodiment does not limit this.

[0060] Specifically, Figure 1 As shown, the metal droplet generating device further includes a thermometer 7, which is used to detect the temperature in the cavity 111 of the containing component 1. The thermometer 7 can provide real-time feedback of the temperature information in the cavity 111, so that the temperature in the cavity 111 can be within a desired range, ensuring that the solid metal can be melted into liquid metal in the containing component 1.

[0061] In this embodiment, if Figure 1 As shown, the metal droplet generating device further includes a barometer 8, which is used to detect the air pressure in the cavity 111 containing the component 1. The barometer 8 can provide real-time feedback of the air pressure information in the cavity 111 to ensure that the air pressure in the cavity 111 is within the required range.

[0062] Specifically, a second heating element is disposed on the outer periphery of the second pipe 32, and the second heating element is used to heat the second pipe 32 so that the second pipe 32 can be heated as required. In this embodiment, the second heating element is a resistance wire; in other embodiments, the second heating element is a heater. It should be noted that any structure in the prior art that can heat the second pipe 32 can be used as the second heating element in this embodiment, and this embodiment does not limit this.

[0063] Specifically, Figure 1 As shown, the droplet generating assembly 4 includes a droplet generator 41 and a second gas cylinder 42. The droplet generator 41 is connected to the cavity 111 of the accommodating assembly 1 through the second pipe 32. The second gas cylinder 42 is connected to the droplet generator 41 through the third pipe 33. The second gas cylinder 42 can pump gas into the droplet generator 41 so that the droplet generator 41 emits metal droplets. By pumping gas into the droplet generator 41 through the second gas cylinder 42, the emission process of the metal droplets can be accurately controlled. By adjusting the pressure and flow of the gas, the size and speed of the ejected metal droplets can be changed; when the gas is pumped into the droplet generator 41, a stable airflow can be formed, which helps the stability of the metal droplets during the emission process.

[0064] In this embodiment, the second gas cylinder 42 can apply a gas pressure of 0.1 MPa-50 MPa to the liquid droplet generator 41. It should be noted that the gas pumped into the liquid droplet generator 41 by the second gas cylinder 42 is an inert gas.

[0065] Specifically, Figure 1As shown, the generating device further includes a recovery container 5, into which metal droplets can be sprayed, and the recovery container 5 is connected to the containing component 1 through a fourth pipe 34. The recovery container 5 can collect the metal droplets emitted by the droplet generator 41, and under the action of gravity, the metal droplets flow back from the recovery container 5 to the containing component 1, thereby realizing the recycling of metal resources.

[0066] In this embodiment, if Figure 1 As shown, the recovery container 5 and the fourth pipeline 34 can be heated so that a dense oxide layer is formed on the inner walls of the recovery container 5 and the fourth pipeline 34 to prevent the liquid metal from dissolving the recovery container 5 and the fourth pipeline 34 when flowing in the recovery container 5 and the fourth pipeline 34, thereby improving the service life and stability of the generating device; the recovery container 5 and the fourth pipeline 34 can be cooled slowly to prevent the local liquid metal from solidifying due to the cooling rate being too fast, thereby avoiding the problem of blockage of the generating device.

[0067] Specifically, a third heating element is disposed on the outer periphery of the fourth pipe 34, and the third heating element is used to heat the fourth pipe 34, so that the third pipe 33 can be heated as needed. In this embodiment, the third heating element is a resistance wire; in other embodiments, the third heating element is a heater. It should be noted that any structure in the prior art that can heat the fourth pipe 34 can be used as the third heating element in this embodiment, and this embodiment does not limit this.

[0068] Specifically, Figure 1 As shown, the metal droplet generating device further includes a vacuum component 6, which has a vacuum chamber 611, and at least part of the droplet generating component 4 and the recovery container 5 are located in the vacuum chamber 611. The metal droplets ejected from the droplet generating component 4 are in a vacuum environment, satisfying the generation conditions of the extreme ultraviolet light source.

[0069] In this embodiment, if Figure 1 As shown, the vacuum assembly 6 includes a vacuum component 61 and a vacuum pump 62 . The vacuum component 61 has the above-mentioned vacuum chamber 611 . The vacuum pump 62 is connected to the vacuum component 61 for evacuating the vacuum component 61 .

[0070] like Figure 2 As shown, this embodiment also provides a method for generating metal droplets, based on the above-mentioned metal droplet generating device, comprising the following steps:

[0071] S1, the first gas cylinder 2 pumps air or oxygen into the containing component 1;

[0072] S2, the containing component 1, the second pipe 32 and the droplet generating component 4 are heated to a first preset temperature and maintained for a preset time;

[0073] S3, adding solid metal to the containing component 1, and heating the containing component 1 to a second preset temperature to melt the solid metal into liquid metal;

[0074] S4, detecting whether the oxygen concentration in the containing component 1 and the droplet generating component 4 is the target oxygen concentration, if so, proceeding to step S5, if not, the first gas cylinder 2 pumps inert gas into the containing component 1 and the droplet generating component 4;

[0075] S5, the containing component 1, the second pipe 32 and the droplet generating component 4 are heated to a third preset temperature;

[0076] S6. The first gas cylinder 2 pumps an inert gas into the containing component 1 to make the liquid metal flow to the droplet generating component 4, and the droplet generating component 4 emits metal droplets.

[0077] First, air or oxygen is pumped into the containing component 1 through the first gas cylinder 2, so that the oxygen concentration in the containing component 1, the second pipe 32 and the droplet generating component 4 is relatively high, and then the containing component 1, the second pipe 32 and the droplet generating component 4 are heated to a first preset temperature and maintained for a preset time, so that a dense oxide layer is formed on the inner walls of the containing component 1, the second pipe 32 and the droplet generating component 4 to prevent the subsequent liquid metal from dissolving the three when flowing in the containing component 1, the second pipe 32 and the droplet generating component 4, thereby improving the service life and stability of the generating device; after adding solid metal to the containing component 1, the containing component 1 is heated to a second preset temperature so that the solid metal melts into liquid metal, and then the first gas cylinder 2 is used to pump inert gas into the containing component 1 and the droplet generating component 4 to ensure that the liquid metal can flow in an environment with a target oxygen concentration to prevent the liquid metal from being oxidized; the containing component 1, the second pipe 32 and the droplet generating component 4 are heated to a third preset temperature to prevent the liquid metal from solidifying during the flow process and emitting metal droplets through the droplet generating component 4.

[0078] Specifically, in step S2, the first preset temperature is 200°C-500°C, and the preset time is 24h-48h.

[0079] Specifically, in step S3, the second preset temperature is 200°C-300°C.

[0080] Specifically, in step S4, the target oxygen concentration is 10 -3 %-10 -11 %.

[0081] Specifically, in step S5, the third preset temperature is 200°C-500°C.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A device for generating metal droplets, characterized in that: include: A containing component (1) having a cavity (111), in which solid metal can be contained, and the containing component (1) can be heated to melt the solid metal into liquid metal; A first gas cylinder (2) is connected to the cavity (111) of the containing assembly (1) through a first pipeline (31), and the first gas cylinder (2) is capable of pumping gas into the containing assembly (1); The droplet generating component (4) is connected to the cavity (111) of the containing component (1) through a second pipe (32); the second pipe (32) and the droplet generating component (4) can both be heated; and the droplet generating component (4) can emit metal droplets.

2. The metal droplet generating device according to claim 1, characterized in that: The receiving assembly (1) comprises: A containing tank (11), the containing tank (11) having the cavity (111); A first heating element (12) is arranged on the outer periphery of the containing tank (11), and the first heating element (12) is used to heat the containing tank (11).

3. The metal droplet generating device according to claim 1, characterized in that: The droplet generating assembly (4) comprises: a droplet generator (41) connected to the cavity (111) of the containing component (1) through the second pipe (32); The second gas cylinder (42) is connected to the liquid droplet generator (41) through a third pipe (33), and the second gas cylinder (42) can pump gas into the liquid droplet generator (41) so that the liquid droplet generator (41) emits the metal droplets.

4. The device for generating metal droplets according to any one of claims 1 to 3, characterized in that: The metal droplet generating device also includes: A recovery container (5), into which the metal droplets can be sprayed, and the recovery container (5) is connected to the containing component (1) via a fourth pipe (34).

5. The metal droplet generating device according to claim 4, characterized in that: The metal droplet generating device also includes: A vacuum component (6), wherein the vacuum component (6) has a vacuum chamber (611), and at least a portion of the droplet generating component (4) and the recovery container (5) are located in the vacuum chamber (611).

6. The metal droplet generating device according to claim 5, characterized in that: The vacuum assembly (6) comprises: A vacuum member (61) having the vacuum chamber (611); A vacuum pump (62) is connected to the vacuum component (61), and the vacuum pump (62) is used to evacuate the vacuum component (61).

7. The device for generating metal droplets according to any one of claims 1 to 3, characterized in that: The metal droplet generating device also includes: A thermometer (7), the thermometer (7) being used to detect the temperature inside the cavity (111) of the containing component (1).

8. The device for generating metal droplets according to any one of claims 1 to 3, characterized in that: The metal droplet generating device also includes: A barometer (8), the barometer (8) being used to detect the air pressure in the cavity (111) of the containing component (1).

9. A method for generating metal droplets, based on the metal droplet generating device according to any one of claims 1 to 8, characterized in that: The method for generating metal droplets comprises the following steps: S1. The first gas cylinder (2) pumps air or oxygen into the containing component (1); S2, the containing component (1), the second pipe (32) and the droplet generating component (4) are heated to a first preset temperature and maintained for a preset time; S3, adding the solid metal to the containing component (1), and heating the containing component (1) to a second preset temperature to melt the solid metal into the liquid metal; S4, detecting whether the oxygen concentration in the containing component (1) and the droplet generating component (4) is the target oxygen concentration, if so, proceeding to step S5, if not, pumping an inert gas into the containing component (1) and the droplet generating component (4) through the first gas cylinder (2); S5, the containing component (1), the second pipe (32) and the droplet generating component (4) are heated to a third preset temperature; S6. The first gas cylinder (2) pumps an inert gas into the containing component (1) so that the liquid metal flows to the droplet generating component (4), and the droplet generating component (4) emits the metal droplets.

10. The method for generating metal droplets according to claim 9, characterized in that: In step S2, the first preset temperature is 200°C-500°C, and the preset time is 24h-48h.

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