Capillary array discharge double-vacuum side collection 13.5 nm light source device

Abstract

The invention discloses a light source device for collecting 13.5 nm through capillary array discharge and double vacuum side faces, and belongs to the technical field of extreme ultraviolet lithography light sources. The light source device comprises a capillary array, electrodes arranged at the two ends of the capillary array, a vacuum discharge chamber arranged outside the electrodes in a sleeving mode and a collection window formed in the middle of one side of the vacuum discharge chamber. The capillary tube array is composed of a plurality of capillary tubes, the capillary tubes are made of glass materials, and the electrodes are made of tungsten copper materials. According to the light source device, the output power of extreme ultraviolet light is greatly improved, the requirement of extreme ultraviolet lithography production can be met through low discharge repetition frequency, meanwhile, electrode scraps, pipe wall scraps and light source impurities are greatly reduced, output of the extreme ultraviolet light is facilitated, a side face collection mode is adopted, and compared with traditional end face collection, the light source device has the advantages of being simple in structure and convenient to use. The light-emitting surface area of the plasma is greatly increased, and the collection amount of the extreme ultraviolet light is also increased.

Description

Technical Field

[0001] The present application relates to the technical field of extreme ultraviolet lithography light sources, and in particular to a capillary array discharge double vacuum side collection 13.5nm light source device. Background Art

[0002] The 13.5nm wavelength extreme ultraviolet (EUV) light source plays a key role in extreme ultraviolet lithography (EUVL) technology. It can provide circuit feature line width within the 10nm technology node and maintain sufficient focal depth, so it has been widely used in large-scale industrial production. Extreme ultraviolet light sources mainly come from synchrotron radiation sources, laser plasma sources, gas discharge plasma sources and laser discharge composite plasma sources. Although synchrotron radiation sources can produce high-quality extreme ultraviolet light, they are expensive, complex in equipment, difficult to operate, and the electron injection process is cumbersome, making them unsuitable for large-scale industrial production; laser plasma sources convert electrical energy into light energy and then into plasma radiation energy. Although they can produce extreme ultraviolet light, their energy conversion efficiency is low; in addition, the plasma temperature and density in laser plasma sources are difficult to accurately control, resulting in an unstable light-emitting process. Even if the required ions are generated, the required wavelength of extreme ultraviolet light may not be emitted. At the same time, laser parameters, target material selection, target shape processing, vacuum control, and problems such as target debris and light source impurities are also difficult problems that need to be solved in the application of laser plasma light sources. Therefore, this light source is rarely used directly in the industrial production of extreme ultraviolet lithography.

[0003] Among them, laser plasma and discharge plasma can both be candidates for 13.5nm extreme ultraviolet light sources. Laser tinning targets is a low-cost option because the price of metallic tin is relatively cheap. However, the power of extreme ultraviolet light radiated by laser plasma light sources and discharge plasma light sources is low, and it needs to go through a series of optical paths before reaching the exposure platform, which limits their application in industrial production. In order to increase the total output power of extreme ultraviolet light, the frequency of laser target shooting or the repetition frequency of discharge can be increased, but this will be accompanied by the generation of a large amount of debris, such as impurity debris and splash debris associated with laser plasma, electrode debris associated with discharge plasma, and tube wall debris and electrode debris generated by capillary discharge devices. If these debris emit stray light, it will affect the purity of the light source and may also absorb 13.5nm extreme ultraviolet light, thereby reducing the light efficiency.

[0004] Therefore, the following problems exist in the prior art when ceramic capillary discharge occurs: first, electrode ablation generally occurs during capillary discharge, resulting in electrode debris; second, capillary discharge is usually accompanied by inner wall erosion, resulting in debris on the tube wall; third, the working substance in the capillary may react with the debris in a plasma state, thereby generating light source impurities, and these debris and light source impurities may radiate stray light of other wavelengths and absorb useful extreme ultraviolet light; finally, capillary discharge generally adopts an end-face collection method, however, since the end surface area of ​​the pinched plasma light emission in the capillary is small, the collection efficiency and power are low.

[0005] Therefore, the present application provides a capillary array discharge double vacuum side collection 13.5nm light source device to solve the above problems. Summary of the invention

[0006] The present application provides a capillary array discharge double vacuum side collection 13.5nm light source device, which aims to solve the problems of debris generated by electrode ablation and inner wall erosion, light source impurities generated by the reaction of working material and debris, stray light radiation and extreme ultraviolet light absorption, and low collection efficiency and power caused by the end face collection method in the prior art of ceramic capillary discharge mentioned in the background technology.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a capillary array discharge double vacuum side collection 13.5nm light source device, comprising a capillary array, electrodes arranged at both ends of the capillary array, a vacuum discharge chamber sleeved outside the electrodes, and a collection window opened at the middle position of one side of the vacuum discharge chamber for collecting extreme ultraviolet light;

[0008] The capillary array is composed of a plurality of capillaries, the capillaries are made of glass, and the electrodes are made of tungsten-copper;

[0009] The light source device also includes an air inlet pipe and an exhaust pipe for exhaust gas emission arranged outside the vacuum discharge chamber and connected to the inside of the capillary array, a secondary pre-ionization arranged outside the vacuum discharge chamber and connected to the air inlet pipe, and a primary pre-ionization connected to the secondary pre-ionization and an external gas supply system; by using a capillary array composed of multiple capillaries for discharge, multiple capillaries can emit light at the same time, thereby significantly increasing the light-emitting surface area of ​​the plasma and improving the output power of the extreme ultraviolet light, wherein the capillary array is made of glass and the electrode is made of tungsten copper. The debris generated by electrode ablation and inner wall erosion can be reduced. At the same time, the combined design of the exhaust pipe and the air inlet pipe can help to discharge the generated trace debris and light source impurities. In addition, a collection window is set on one side of the vacuum discharge chamber for side collection. Compared with the traditional end face collection, this side collection method can greatly increase the luminous surface area of ​​the plasma and increase the collection amount of extreme ultraviolet light. In addition, this design allows the luminous area to be separated from the collection area, thereby reducing the influence of discharge debris, tube wall debris and light source impurities on the extreme ultraviolet light, thereby improving the purity of the light source.

[0010] Preferably, in order to ensure the performance of the vacuum discharge chamber, the vacuum discharge chamber is a cylindrical stainless steel shell; the cylindrical stainless steel shell has good structural strength and sealing performance, and can withstand the high pressure and high temperature environment generated during the discharge process. At the same time, the stainless steel material has excellent corrosion resistance and wear resistance, and can extend the service life of the vacuum discharge chamber. In addition, the cylindrical design is conducive to optimizing the electric field distribution and improving the discharge efficiency and stability.

[0011] Preferably, in order to ensure the purity and stability of the light source, the vacuum discharge chamber and the capillary array are isolated and sealed, and the vacuum discharge chamber and the capillary array are in different vacuum environments; through the isolation and sealing, the vacuum discharge chamber and the capillary array can be maintained at different vacuum degrees, respectively, which helps to reduce the impact of impurities generated during the discharge process on the internal environment of the capillary array, improve the purity and stability of the light source, and at the same time, different vacuum environments can also optimize the discharge conditions and plasma performance, further improving the output power and collection efficiency of extreme ultraviolet light.

[0012] Preferably, in order to ensure the output power and collection efficiency of the extreme ultraviolet light, the vacuum discharge chamber and the capillary array are in different vacuum environments; different vacuum environments can also optimize the discharge conditions and plasma performance, further improving the output power and collection efficiency of the extreme ultraviolet light.

[0013] Preferably, in order to ensure the smooth progress of the discharge process, the electrode includes a cathode and an anode, and the cathode and the anode are respectively arranged at the two ends of the capillary array; the separate setting of the cathode and the anode is conducive to forming a stable electric field distribution and promoting the smooth progress of the discharge process. At the same time, this design can also conveniently adjust the voltage and current between the electrodes to optimize the discharge conditions and plasma performance.

[0014] Preferably, in order to facilitate the control of gas, a gas valve is fixedly arranged between the first-level pre-ionization and the gas supply system; the setting of the gas valve can accurately control the gas flow and pressure entering the first-level pre-ionization, thereby optimizing the pre-ionization effect and discharge conditions. At the same time, the gas valve can also serve as a safety device to quickly cut off the gas supply in an emergency to protect the safety of the device and personnel.

[0015] Preferably, in order to ensure the smooth progress of the discharge process and the stability of the light source, a barometer for monitoring the air pressure value inside the capillary array is fixedly arranged between the air inlet pipe and the capillary array; the barometer can monitor the air pressure value inside the capillary array in real time, and provide accurate data support for operators, which helps to timely discover and solve abnormal air pressure problems, ensure the smooth progress of the discharge process and the stability of the light source, and at the same time, the air pressure data can also be used to optimize the discharge conditions and plasma performance, and further improve the output power and collection efficiency of extreme ultraviolet light.

[0016] Preferably, in order to ensure the collection efficiency of extreme ultraviolet light, a collection hole is provided on the collection window, and the aperture of the collection hole is 150 mm; a larger collection hole aperture can allow more extreme ultraviolet light to pass through and enter the collection area, thereby improving the collection efficiency of the light source.

[0017] The capillary array discharge double vacuum side collection 13.5nm light source device discharges by using a capillary array composed of multiple capillaries, wherein the multiple capillaries can emit light simultaneously, thereby increasing the light-emitting surface area of ​​the plasma, thereby increasing the output power of the extreme ultraviolet light;

[0018] The capillary array discharge double vacuum side collection 13.5nm light source device uses a glass capillary array and tungsten copper electrodes to reduce the debris generated by electrode ablation and inner wall erosion. At the same time, the combined design of the exhaust pipe and the air inlet pipe helps to discharge the trace debris and light source impurities.

[0019] The capillary array discharge double vacuum side collection 13.5nm light source device can perform side collection by setting a collection window on one side of the vacuum discharge chamber. Compared with the traditional end face collection, this side collection method can greatly increase the luminous surface area of ​​the plasma and increase the collection amount of extreme ultraviolet light. At the same time, this design allows the luminous area and the collection area to be separated, thereby reducing the impact of discharge debris, tube wall debris and light source impurities on the extreme ultraviolet light, thereby improving the purity of the light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the process structure of a capillary array discharge double vacuum side collection 13.5nm light source device;

[0021] Figure 2 This is a schematic diagram of the structure of a capillary array discharge double vacuum side collection 13.5nm light source device.

[0022] In the figure:

[0023] 1. Capillary array;

[0024] 2. Electrode;

[0025] 3. Vacuum discharge chamber;

[0026] 4. Collection window;

[0027] 5. Cathode;

[0028] 6. Anode;

[0029] 7. Intake pipe;

[0030] 8. Exhaust pipe;

[0031] 9. Secondary preionization;

[0032] 10. First-stage preionization;

[0033] 11. Air valve;

[0034] 12. Barometer. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] This embodiment provides a capillary array discharge double vacuum side collection 13.5nm light source device, such as Figure 1-Figure 2As shown, the light source device includes a capillary array 1, electrodes 2 arranged at both ends of the capillary array 1, a vacuum discharge chamber 3 sleeved on the outside of the electrode 2, and a collection window 4 opened at the middle position of one side of the vacuum discharge chamber 3 for collecting extreme ultraviolet light; the capillary array 1 is composed of a plurality of capillaries, the capillaries are made of glass material, and the electrode 2 is made of tungsten copper material; the light source device also includes an air inlet pipe 7 arranged outside the vacuum discharge chamber 3 and connected to the inside of the capillary array 1 and an exhaust pipe 8 for exhaust gas discharge, a secondary pre-ionization 9 arranged outside the vacuum discharge chamber 3 and connected to the air inlet pipe 7, and a primary pre-ionization 10 connected to the secondary pre-ionization 9 and an external gas supply system.

[0037] Among them, in order to ensure the smooth progress of the discharge process, the electrode 2 includes a cathode 5 and an anode 6, and the cathode 5 and the anode 6 are respectively arranged at the two ends of the capillary array 1; the separate setting of the cathode 5 and the anode 6 is conducive to forming a stable electric field distribution and promoting the smooth progress of the discharge process. At the same time, this design can also conveniently adjust the voltage and current between the electrodes 2 to optimize the discharge conditions and plasma performance.

[0038] In addition, in order to further ensure the purity and stability of the light source as well as the output power and collection efficiency of the extreme ultraviolet light, the vacuum discharge chamber 3 and the capillary array 1 are isolated and sealed, and the vacuum discharge chamber 3 and the capillary array 1 are in different vacuum environments; through isolation and sealing, the vacuum discharge chamber 3 and the capillary array 1 can be maintained at different vacuum degrees, respectively, which helps to reduce the impact of impurities generated during the discharge process on the internal environment of the capillary array 1, and improve the purity and stability of the light source. At the same time, different vacuum environments can also optimize the discharge conditions and plasma performance, and further improve the output power and collection efficiency of the extreme ultraviolet light.

[0039] It should be added that the inner diameter of the capillary is 10mm, the wall thickness is 1-2mm, and the length is 100mm. The voltage during discharge is 15-25kV, the maximum peak value of the discharge current is 20kA, and the pulse width is 150ns. When used in this way, multiple capillaries can emit light at the same time, making the luminous surface area of ​​the plasma large, so that the efficiency of side collection is also high, and the 13.5nm light power is greatly improved.

[0040] When in use, the cathode 5 is first discharged through the anode 6. At this time, a high-temperature and high-density plasma is generated in the capillary array 1. At the same time, xenon gas is provided to the primary pre-ionization 10 through an external gas supply system. The gas pressure of the xenon gas is maintained at tens of Pa. At this time, the primary pre-ionization 10 ionizes the introduced xenon gas into +1 or +2 valence xenon ions. Then, the xenon ions ionized into +1 or +2 valence will be ionized into +5 or +6 valence xenon ions through the secondary pre-ionization 9. The xenon ions ionized into +5 or +6 valence will enter the capillary array 1 through the inlet pipe 7 and then be ionized into Xe 10+Since the capillary array 1 is arranged in the vacuum discharge chamber 3, and the capillary array 1 and the vacuum discharge chamber 3 are isolated and sealed, and a collecting window 4 is opened at the middle position of one side of the vacuum discharge chamber 3, the luminous plasma is located in the capillary array 1, and the collection area of ​​the extreme ultraviolet light is located in the stainless steel vacuum discharge chamber 3, so that the luminous area is separated from the collection area, which is beneficial to improve the output of the extreme ultraviolet light. In addition, the capillary array 1 made of glass material has good stability and very little tube wall debris, and the electrode 2 made of tungsten copper material has a small amount of ablation of the electrode 2, so that the impurities of the light source are greatly reduced. Finally, after the discharge is completed, the exhaust gas can be smoothly discharged from the capillary array 1 through the exhaust pipe 8, and then new xenon gas can be continuously introduced into the capillary array 1 to discharge again.

[0041] Specifically, the vacuum discharge chamber 3 is a cylindrical stainless steel shell; the cylindrical stainless steel shell has good structural strength and sealing performance, and can withstand the high pressure and high temperature environment generated during the discharge process. At the same time, the stainless steel material has excellent corrosion resistance and wear resistance, which can extend the service life of the vacuum discharge chamber 3. In addition, the cylindrical design is conducive to optimizing the electric field distribution and improving the discharge efficiency and stability.

[0042] Furthermore, a gas valve 11 is fixedly arranged between the first-stage pre-ionization 10 and the gas supply system; the operator can accurately control the gas flow and pressure entering the first-stage pre-ionization 10 by operating the gas valve 11, so as to optimize the pre-ionization effect and discharge conditions, and during the gas supply process, the operator can also close the gas valve 11 to quickly cut off the gas supply in an emergency to ensure the safety of the device and personnel.

[0043] Furthermore, a barometer 12 for monitoring the air pressure value inside the capillary array 1 is fixedly arranged between the air inlet pipe 7 and the capillary array 1; during the discharge process, the air pressure value inside the capillary array 1 can be monitored in real time by the arranged barometer 12, providing accurate data support for the operator, helping the operator to promptly discover and solve the problem of abnormal air pressure, ensuring the smooth progress of the discharge process and the stability of the light source, and improving the output power and collection efficiency of the extreme ultraviolet light.

[0044] It can be understood that in order to ensure the collection efficiency of extreme ultraviolet light, a collection hole is provided on the collection window 4, and the aperture of the collection hole is 150 mm; a larger collection hole aperture can allow more extreme ultraviolet light to pass through and enter the collection area, thereby improving the collection efficiency of the light source.

[0045] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes according to the technical solution and concept of the present application within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A capillary array discharge double vacuum side collection 13.5nm light source device, characterized in that: It comprises a capillary array (1), electrodes (2) arranged at both ends of the capillary array (1), a vacuum discharge chamber (3) sleeved outside the electrode (2), and a collection window (4) provided at the middle of one side of the vacuum discharge chamber (3) for collecting extreme ultraviolet light; The capillary array (1) is composed of a plurality of capillaries, the capillaries are made of glass material, and the electrodes (2) are made of tungsten-copper material; The light source device further comprises an air inlet pipe (7) and an exhaust pipe (8) for exhaust gas, which are arranged outside the vacuum discharge chamber (3) and communicated with the inside of the capillary array (1), a secondary pre-ionization (9) arranged outside the vacuum discharge chamber (3) and communicated with the air inlet pipe (7), and a primary pre-ionization (10) which is communicated with the secondary pre-ionization (9) and an external air supply system.

2. The capillary array discharge double vacuum side collection 13.5nm light source device according to claim 1, characterized in that: The vacuum discharge chamber (3) is a cylindrical stainless steel shell.

3. The capillary array discharge double vacuum side collection 13.5nm light source device according to claim 2, characterized in that: The vacuum discharge chamber (3) and the capillary array (1) are isolated and sealed.

4. The capillary array discharge double vacuum side collection 13.5nm light source device according to claim 3, characterized in that: The vacuum discharge chamber (3) and the capillary array (1) are in different vacuum environments.

5. The capillary array discharge double vacuum side collection 13.5nm light source device according to claim 1, characterized in that: The electrode (2) comprises a cathode (5) and an anode (6), and the cathode (5) and the anode (6) are respectively arranged at two ends of the capillary array (1).

6. The capillary array discharge double vacuum side collection 13.5nm light source device according to claim 1, characterized in that: A gas valve (11) is fixedly arranged between the primary pre-ionization (10) and the gas supply system.

7. The capillary array discharge double vacuum side collection 13.5nm light source device according to claim 1, characterized in that: A barometer (12) for monitoring the air pressure value in the capillary array (1) is fixedly arranged between the air inlet pipe (7) and the capillary array (1).

8. The capillary array discharge double vacuum side collection 13.5nm light source device according to claim 1, characterized in that: The collecting window (4) is provided with a collecting hole, and the diameter of the collecting hole is 150 mm.

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