Gas circuit device and extreme ultraviolet light generator applied by gas circuit device

Abstract

The invention discloses a gas circuit device which is suitable for an extreme ultraviolet light generating cabin, the extreme ultraviolet light generating cabin is provided with a vacuum cavity and a gas circuit cavity which are mutually independent, an ionization platform is arranged in the vacuum cavity, an optical fiber communicated with the ionization platform is arranged on the ionization platform, the gas circuit cavity is provided with a gas circuit system, and the gas circuit system comprises a gas inlet pipeline. The end part of the gas inlet pipeline is connected with two branch pipes through valves and is respectively communicated with the ionization platform and the vacuum cavity, and under the action of pressure difference, the flow direction of reaction gas in the two branch pipes is adjusted by opening and closing the passages of the branch pipes communicated with the vacuum cavity. According to the invention, the flow direction of the reaction gas in the second branch pipe and the flow direction of the reaction gas in the gas inlet pipeline can be adjusted by opening and closing the passage of the first branch pipe, so that the reaction gas enters the vacuum cavity through the first branch pipe under the action of pressure difference, and gas extraction is facilitated; therefore, the emptying rate and the vacuumizing rate of the reaction gas in the pipeline are improved, and replacement of the reaction gas is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of extreme ultraviolet light instruments, and particularly to a gas path device and an extreme ultraviolet light generator to which the gas path device is applied. Background Art

[0002] Extreme ultraviolet light, also known as extreme ultraviolet radiation, refers to electromagnetic radiation with wavelengths ranging from 121 nanometers to 10 nanometers in the electromagnetic spectrum. Extreme ultraviolet light is commonly used in lithography technology. Extreme ultraviolet light is generated in a vacuum environment by discharging and exciting a specific gas (such as xenon). This process involves high-energy electrons bombarding gas atoms, ionizing them and releasing extreme ultraviolet light. Specifically, in the process of generating extreme ultraviolet light in an optical fiber, an inert gas is a necessary condition for generating extreme ultraviolet light. During the generation of extreme ultraviolet light, different inert gases need to be introduced into the optical fiber to obtain extreme ultraviolet light of different wavelength bands.

[0003] When replacing the gas, it is necessary to evacuate the gas in the vacuum cavity and the gas path pipeline of the extreme ultraviolet light generator. If the gas path pipeline is directly pulled out from the ionization station and the pipeline is evacuated, it is necessary to break the vacuum of the vacuum cavity, which not only requires recalibrating the position of the optical fiber, but also causes other gases to enter the vacuum cavity, affecting the cleanliness of the vacuum cavity. Therefore, generally, the gas is directly pumped out through a vacuum pump at the gas extraction port of the vacuum cavity. The gas in the pipeline will first enter the ionization station, then flow through the optical fiber into the vacuum cavity, and finally be pumped out. This method of gas extraction in a vacuum environment, due to the large amount of gas in the gas path pipeline, a large amount of gas can only be discharged into the vacuum cavity through the small pores in the optical fiber, resulting in an extremely slow vacuum pumping rate and causing great inconvenience in replacing the reaction gas. Summary of the Invention

[0004] The object of the present invention is to solve the problems in the above background art, and to provide an extreme ultraviolet light generator with a gas path device and its application.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] A gas path device is applicable to an extreme ultraviolet light generation chamber. The extreme ultraviolet light generation chamber is provided with an independent vacuum cavity and a gas path cavity. An ionization station is arranged in the vacuum cavity, and an optical fiber connected thereto is arranged on the ionization station. The gas path cavity is provided with a gas path system. The gas path system includes an inlet gas pipeline. The end of the inlet gas pipeline is connected to two branch pipes through valves, which are respectively communicated with the ionization station and the vacuum cavity. Under the action of the pressure difference, by opening and closing the passage of the branch pipe communicating with the vacuum cavity, the flow direction of the reaction gas in the two branch pipes is adjusted.

[0007] As a further aspect of the present invention: The inlet gas pipeline is provided with an inlet gas main valve and a flow regulator along the gas flow direction.

[0008] As a further solution of the present invention: the branch pipe connecting the ionization stage is the second branch pipe, and the branch pipe connecting the vacuum chamber is the first branch pipe, and the output end of the first branch pipe is located in the vacuum chamber.

[0009] As a further solution of the present invention: the first branch pipe is provided with a control valve, and the control valve is used to open and close the passage of the first branch pipe.

[0010] As a further solution of the present invention: the valve is a three-way valve.

[0011] An extreme ultraviolet light generator, comprising: an extreme ultraviolet light generation chamber, a test chamber and a light source processing chamber are suspended and installed on the side wall of the extreme ultraviolet light generation chamber, a collimation device is arranged in the test chamber, and the collimation device is used to inject test light into an optical fiber. The extreme ultraviolet light generation chamber is provided with a light passing device and a moving device for adjusting the position of the optical fiber. The collimation device cooperates with the moving device to collimate the optical fiber through the test light. The light source processing chamber is provided with a focusing device, and the focusing device is used to inject a red laser beam into the optical fiber. An air path device is arranged in the extreme ultraviolet light generation chamber, and the air path device is used to provide reaction gas for the optical fiber. The focusing device cooperates with the air path device to ionize the reaction gas in the optical fiber with the red laser beam to generate extreme ultraviolet light.

[0012] As a further solution of the present invention: independent chambers are arranged in the extreme ultraviolet light generation chamber, and the chambers include an atmospheric pressure chamber, a vacuum chamber, a transmission chamber and an air path chamber. An optical outlet is opened in the transmission chamber, and both the vacuum chamber and the transmission chamber are set to a vacuum environment suitable for the propagation of extreme ultraviolet light.

[0013] As a further solution of the present invention: the extreme ultraviolet light generation chamber is connected to a slit adjustment device, and the slit adjustment device includes two filter glass slides arranged up and down in the transmission chamber. The gap between the two filter glass slides serves as a slit for passing extreme ultraviolet light. Moving the positions of the two filter glass slides is used to adjust the slit to filter out stray light in the extreme ultraviolet light.

[0014] As a further solution of the present invention: the focusing device includes two CCD cameras, and the pixel points where the light spots are located in the two CCD cameras are compared to adjust the reflection angle of the red laser beam.

[0015] As a further solution of the present invention: the vacuum chamber and the transmission chamber are connected and communicated through a differential system, and the differential system is used to control the air pressure difference between the two chambers.

[0016] The beneficial effects of the present invention:

[0017] (1) In the present invention, by performing an opening and closing operation on the passage of the first branch pipe, the flow direction of the reaction gas in the second branch pipe and the reaction gas in the intake pipe can be adjusted, so that the reaction gas enters the vacuum chamber through the first branch pipe under the action of the pressure difference, facilitating air extraction, thereby improving the discharge rate of the reaction gas in the pipeline and the vacuum pumping rate, and facilitating the replacement of the reaction gas.

[0018] (2) In the present invention, the optical fiber is collimated and detected by the inspection light emitted by the collimation device, and then the position of the optical fiber is adjusted in cooperation with the moving device, which is beneficial to the positioning of the optical fiber.

[0019] (3) In the present invention, the optical fiber after the adjusting device adjusts its position can ensure that the red laser beam is coaxial with the optical fiber, which is beneficial to the generation of extreme ultraviolet light.

[0020] (4) In the present invention, the focusing device focuses and adjusts the red laser beam, which can improve the coupling efficiency of the optical fiber and can also collimate the optical path of the red laser beam through the first CCD camera and the second CCD camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 is the front view of the extreme ultraviolet light generator of the present invention;

[0023] Figure 2 is the rear view of the extreme ultraviolet light generator of the present invention;

[0024] Figure 3 is the schematic internal structure diagram of the housing in the extreme ultraviolet light generator of the present invention;

[0025] Figure 4 is Figure 3 the schematic internal structure diagram of the inspection chamber in

[0026] Figure 5 is Figure 3 the structural schematic diagram of the light source processing chamber in

[0027] Figure 6 is Figure 5 the schematic internal structure diagram of the light source processing chamber in

[0028] Figure 7 is Figure 3 the structural schematic diagram of the extreme ultraviolet light generation chamber in

[0029] Figure 8 is Figure 3 the structural schematic diagram of the extreme ultraviolet light generation chamber in

[0030] Figure 9 is Figure 7Schematic diagram of the internal structure of the extreme ultraviolet light generation chamber;

[0031] Figure 10 is Figure 9 An enlarged view of area A in

[0032] Figure 11 is Figure 9 An enlarged view of area B in

[0033] Figure 12 is Figure 9 Schematic diagram of the structure of the adjustment device in

[0034] Figure 13 is Figure 12 Schematic diagram of the structure of the ionization stage in

[0035] Figure 14 is Figure 13 Cross-sectional view of the ionization stage in

[0036] Figure 15 is Figure 12 Bottom view of the optical fiber in

[0037] Figure 16 is Figure 12 Top view of the optical fiber in

[0038] Figure 17 Schematic plan view of the gas path system of the extreme ultraviolet light generator of the present invention;

[0039] Figure 18 Schematic diagram of the structure of the gas path system of the extreme ultraviolet light generator of the present invention;

[0040] Figure 19 is Figure 11 Schematic diagram of the structure of the differential system in

[0041] Figure 20 is Figure 19 Cross-sectional view of the differential system in

[0042] Figure 21 is Figure 7 Schematic diagram of the structure of the slit adjustment device in the transmission cavity in

[0043] In the figure:

[0044] 1. Housing; 2. Extreme ultraviolet light generation chamber; 21. Atmospheric pressure cavity; 22. Vacuum cavity; 23. Transmission cavity; 24. Gas path cavity; 25. First air extraction port; 26. Second air extraction port; 27. Light output port; 28. First light hole; 29. Second light hole; 3. Inspection chamber; 31. Third light hole; 4. Light source processing chamber; 41. Light input port; 42. Fourth light hole; 5. Collimation device; 51. Laser pen; 52. First diaphragm; 53. First silver-plated mirror; 54. Second silver-plated mirror; 55. Third silver-plated mirror; 6. Focusing device; 61. First electronically controlled femtosecond mirror; 62. Second diaphragm; 63. Half-wave plate; 64. Convex lens; 65. Second electronically controlled femtosecond mirror; 66. First femtosecond mirror; 67. Wedge prism; 68. Fourth silver-plated mirror; 69. First CCD camera; 610. Second CCD camera; 611. Adjustment knob; 7. Light passing device; 71. Optical switch; 72. Second femtosecond mirror; 73. Third diaphragm; 74. Incident window; 8. Optical fiber; 81. Optical channel; 82. Air inlet hole; 83. Air outlet hole; 9. Moving device; 91. Fixed base; 92. Moving stage; 93. Tension spring; 94. Limit rod; 95. Rotating block; 96. Ionization table; 961. Water inlet channel; 962. Water outlet channel; 963. Air inlet channel; 964. Air outlet channel; 97. Fixed rod; 98. Pressure strip; 99. First adjusting screw rod; 910. Second adjusting screw rod; 10. Cooling system; 101. Water inlet pipeline; 102. Water outlet pipeline; 103. Thermocouple; 104. Return pipeline; 11. Gas path system; 111. Air inlet pipeline; 112. Main air inlet valve; 113. Flow regulator; 114. Three-way valve; 115. First branch pipe; 116. Second branch pipe; 117. Control valve; 118. Vacuum pump; 12. Differential system; 121. First channel; 122. Second channel; 13. Slit adjustment device; 131. Third femtosecond mirror; 132. First adjustment knob; 133. First filter glass sheet; 134. Second filter glass sheet; 135. Second adjustment knob; 136. Third adjustment knob; 137. First observation window; 138. Second observation window. Detailed implementation manners

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] Please refer to Figures 7 - 8 , Figure 11 , Figures 15 - 16The present invention relates to a gas path device, which is applicable to the extreme ultraviolet light generation chamber 2. An independent vacuum cavity 22 and a gas path cavity 24 are provided in the extreme ultraviolet light generation chamber 2. An ionization stage 96 is arranged in the vacuum cavity 22, and an optical fiber 8 connected thereto is arranged on the ionization stage 96. The optical fiber 8 is provided with an optical channel 81. An air inlet hole 82 is opened downward in the optical channel 81, and an air outlet hole 83 is opened upward in the optical channel 81. The reaction gas introduced into the ionization stage 96 enters the optical fiber 8 through the air inlet hole 82, fills the optical channel 81, and then flows into the vacuum cavity 22 from the air outlet hole 83.

[0047] Wherein, the inner diameter of the optical channel 81 is 0.1 mm - 0.2 mm, and the inner diameters of the air inlet hole 82 and the air outlet hole 83 are 0.2 mm - 0.3 mm.

[0048] Figures 17 - 18 As shown, the gas path device includes a gas path system 11. The gas path system 11 is arranged in the gas path cavity 24, and the gas path system 11 is used to provide reaction gas for the optical fiber 8.

[0049] Specifically, the gas path system 11 includes an inlet pipeline 111. An inlet main valve 112 and a flow regulator 113 are arranged on the inlet pipeline 111 along the gas flow direction. The end of the inlet pipeline 111 is connected to two branch pipes through a three-way valve 114. The two branch pipes are respectively a second branch pipe 116 and a first branch pipe 115. The three-way valve 114 is arranged at the connection of the inlet pipeline 111, the second branch pipe 116, and the first branch pipe 115.

[0050] The second branch pipe 116 is connected to the ionization stage 96, and the first branch pipe 115 is connected to the vacuum cavity 22, and the output end of the first branch pipe 115 is located in the vacuum cavity 22. A control valve 117 is further arranged on the first branch pipe 115, and the control valve 117 is used to open and close the passage of the first branch pipe 115. Under the action of the pressure difference, by opening and closing the passage of the first branch pipe 115, the flow direction of the reaction gas in the two branch pipes is adjusted.

[0051] The inventor found that when replacing the reaction gas, if the gas is pumped out through a vacuum pump 118 at the air extraction port (the first air extraction port 25) of the vacuum cavity 22, the residual gas in the second branch pipe 116 and the inlet pipeline 111 will first enter the ionization stage 96, then flow through the optical fiber 8 into the vacuum cavity 22, and finally be pumped out. The second branch pipe 116 and the inlet pipeline 111 are both pipes with conventional apertures, and their inner diameter graduation values are measured in cm, so that there is more residual gas in the second branch pipe 116 and the inlet pipeline 111. A large amount of gas in the optical fiber 8 can only be discharged into the vacuum cavity 22 through the small holes (the optical channel 81, the air inlet hole 82, and the air outlet hole 83) in the optical fiber 8, and it is very difficult to quickly discharge all the reaction gas retained in the inlet pipeline 111 and the second branch pipe 116, resulting in an extremely slow vacuum pumping rate.

[0052] In this embodiment, when generating extreme ultraviolet light, the vacuum pump 118 continuously evacuates the vacuum chamber 22. The input end of the intake pipeline 111 is connected to an external gas source. The main intake valve 112 is opened, and the control valve 117 is closed. The gas source introduces a reaction gas into the intake pipeline 111. The reaction gas flows into the optical fiber 8 after entering the ionization stage 96. The red laser beam in the optical fiber 8 ionizes the reaction gas to generate extreme ultraviolet light. When the reaction gas needs to be replaced, according to the wavelength band of the required extreme ultraviolet light, the corresponding reaction gas is selected. While maintaining the vacuum environment of the vacuum chamber 22, the flow direction of the reaction gas in the second branch pipe 116 and the reaction gas in the intake pipeline 111 is adjusted by opening and closing the passage of the first branch pipe 115.

[0053] Specifically, the main intake valve 112 is closed, and the control valve 117 is opened to make the intake pipeline 111, the first branch pipe 115, and the second branch pipe 116 communicate with each other. Due to the pressure difference, the reaction gases in the intake pipeline 111 and the second branch pipe 116 will change their flow directions and enter the first branch pipe 115. The reaction gas in the first branch pipe 115 will enter the vacuum chamber 22 and be directly pumped out by the vacuum pump 118, so that the reaction gas in the pipeline can be directly introduced into the vacuum chamber 22 without passing through the optical fiber 8 and then be pumped out by the vacuum pump 118. The first branch pipe 115 is also a conventional pipeline, and the graduation value of its inner diameter is usually measured in cm. The speed at which the gas flows from the first branch pipe 115 into the vacuum chamber 22 is significantly higher than the speed at which it flows from the optical fiber 8 into the vacuum chamber 22, thereby improving the evacuation rate of the reaction gas in the pipeline and the vacuum pumping rate, which is convenient for replacing the reaction gas.

[0054] The following table shows the relevant experimental data:

[0055] Table 1 Drainage duration table of reaction gas flowing into the vacuum chamber in different paths

[0056] Exhaust path of reaction gas in the pipeline Duration for exhausting reaction gas completely Discharge into the vacuum chamber from the optical fiber 2h Discharge into the vacuum chamber from the first branch pipe 20 min

[0057] As can be seen from the above table, by flowing the reaction gas in the pipeline into the vacuum chamber 22 from the direction of the first branch pipe 115, its evacuation rate has been effectively improved, which is convenient for the experimenter to replace the reaction gas.

[0058] Please refer to Figures 1 - 3As shown in the figure, the present invention is an extreme ultraviolet light generator, comprising: an extreme ultraviolet light generation chamber 2, with an inspection chamber 3 and a light source processing chamber 4 suspended and installed on the side wall of the extreme ultraviolet light generation chamber 2. The bottom of the inspection chamber 3 and the bottom of the light source processing chamber 4 are suspended on two side walls of the extreme ultraviolet light generation chamber 2 through connectors, such that the top covers of the inspection chamber 3 and the light source processing chamber 4 are both located on the side of the entire extreme ultraviolet light generator. Three connectors are provided on each side wall, and they are installed in a way that three points determine a plane, reducing the processing difficulty and requirements for the outer surface of the chamber body in the early stage. The suspended installation can also make reasonable use of the space of the equipment. An outer shell 1 is provided outside the extreme ultraviolet light generation chamber 2, and the inspection chamber 3 and the light source processing chamber 4 are both located inside the outer shell 1, and the three chambers are fixed in the outer shell 1.

[0059] Please refer to Figures 7 - 8 As shown in the figure, multiple independent cavities are provided in the extreme ultraviolet light generation chamber 2. The cavities include an atmospheric pressure cavity 21, with a vacuum cavity 22 provided on one side of the atmospheric pressure cavity 21. An observation window is also provided on the top cover of the vacuum cavity 22, facilitating the observation of the internal extreme ultraviolet light generation situation. A transmission cavity 23 and an air path cavity 24 located below the transmission cavity 23 are provided on one side of the vacuum cavity 22, and an optical outlet 27 is opened in the transmission cavity 23.

[0060] Among them, please refer to Figure 9 、 Figure 11 、 Figures 19 - 20 As shown in the figure, both the vacuum cavity 22 and the transmission cavity 23 are set to adapt to the vacuum environment for the propagation of extreme ultraviolet light. And the vacuum cavity 22 and the transmission cavity 23 are connected through a differential system 12. The differential system 12 is used to control the air pressure difference between the two cavities, so that there is a difference in the vacuum degree between the vacuum cavity 22 and the transmission cavity 23. In this embodiment, the air pressure in the vacuum cavity 22 is 10 Pa, and the air pressure in the transmission cavity 23 is -4 Pa. The vacuum degree of the transmission cavity 23 is higher than that of the vacuum cavity 22, facilitating the transmission of extreme ultraviolet light.

[0061] Specifically, a first channel 121 with a gradually increasing inner diameter and a second channel 122 with a uniform inner diameter are provided in the differential system 12. The first channel 121 is arranged in the vacuum cavity 22, and the second channel 122 is arranged in the transmission cavity 23, and the first channel 121 and the second channel 122 are coaxially arranged. The inner diameter of the intake end of the first channel 121 is equal to the inner diameter of the outlet end of the second channel 122. The two channels determine a straight line, which can ensure that the reaction gas passes through while also ensuring that the extreme ultraviolet light can pass through the differential system 12 and enter the transmission cavity 23. In addition, the first channel 121 is set as a tapered channel with a gradually increasing inner diameter, which can avoid the situation where the optical path of the extreme ultraviolet light cannot pass through due to an angular deviation during the installation of the differential system 12.

[0062] Please refer to Figure 4 、 Figure 7As shown in the figure, a collimating device 5 is provided in the inspection chamber 3. The collimating device 5 is used to inject inspection light into the optical fiber 8. The collimating device 5 includes a laser pen 51, and the laser pen 51 can emit green light, and the green light is used as the inspection light. At the output end of the laser pen 51, a first diaphragm 52, a first silver-plated mirror 53, a second silver-plated mirror 54, and a third silver-plated mirror 55 are respectively arranged along the transmission direction of the inspection light. After the green light passes through the first diaphragm 52, it is reflected by the first silver-plated mirror 53, the second silver-plated mirror 54, and the third silver-plated mirror 55, and then enters the atmospheric pressure cavity 21 from the third light hole 31 opened in the inspection chamber 3 and the second light hole 29 opened in the extreme ultraviolet light generation chamber 2.

[0063] Please refer to Figures 7 - 10 As shown in the figure, a light passing device 7 and a moving device 9 for adjusting the position of the optical fiber 8 are provided in the extreme ultraviolet light generation chamber 2. The light passing device 7 is located in the atmospheric pressure cavity 21. The light passing device 7 includes an optical switch 71. A second femtosecond mirror 72 is arranged on one side of the optical switch 71. Along the transmission direction of the green light, a third diaphragm 73 and an incident window 74 are arranged on the second femtosecond mirror 72, and the window piece on the incident window 74 is coated with an infrared antireflection film.

[0064] When the collimating device 5 is operating, the second femtosecond mirror 72 needs to be removed (the second femtosecond mirror 72 is fixed in the atmospheric pressure cavity 21 by bolts, and it can be removed by removing the bolts), so that the green light injected into the atmospheric pressure cavity 21 can directly pass through the third diaphragm 73 and the incident window 74 and enter the optical fiber 8 in the vacuum cavity 22. The green light passes through the optical fiber 8 and the differential system 12 and exits from the light outlet 27. A baffle is placed at the light outlet 27. If a green light spot appears on the baffle, it proves that the position of the optical fiber 8 is accurate, and the subsequent extreme ultraviolet light generation operation can be carried out. If no green light spot appears on the baffle, the position of the optical fiber 8 needs to be collimated or corrected.

[0065] Please refer to Figures 7 - 12 As shown in the figure, the collimating device 5 and the moving device 9 cooperate to collimate the optical fiber 8 through the inspection light.

[0066] Specifically, the moving device 9 includes a fixed base 91, and the fixed base 91 is fixedly installed on the vacuum cavity 22. A moving table 92 is also arranged above the fixed base 91. The fixed base 91 is rotatably connected to a rotating block 95 through a bearing. A limiting rod 94 is arranged above the rotating block 95, and the limiting rod 94 is fixedly installed on the moving table 92. An ionization table 96 is arranged in the moving table 92, and the ionization table 96 is connected to a fiber holder fixing the optical fiber 8. The extreme ultraviolet light generation chamber 2 is connected to a first adjusting screw rod 99 and a second adjusting screw rod 910. The first adjusting screw rod 99 is used to drive the rotating block 95 to rotate, and the second adjusting screw rod 910 is used to drive the ionization table 96 to move on the moving table 92.

[0067] In this embodiment, when collimating or correcting the position of the optical fiber 8, rotate the two first adjusting lead screws 99 so that the ends of the first adjusting lead screws 99 move towards the rotating block 95. The rotating block 95 rotates and jacks up the limiting rod 94, and the limiting rod 94 drives the moving stage 92 to move upward until the central axis of the optical fiber 8 and the incident window 74 are in the same plane (i.e., the x-y plane). Then rotate the two second adjusting lead screws 910 so that the ends of the second adjusting lead screws 910 move towards the ionization stage 96. Under the action of the second adjusting lead screws 910, the ionization stage 96 twists on the x-y plane until the optical fiber 8 and the incident window 74 are coaxial, facilitating the subsequent red laser beam passing through the incident window 74 to be coaxial with the optical fiber 8, which is beneficial to generating extreme ultraviolet light. At this time, the central axes of the incident window 74, the optical fiber 8, and the differential system 12 are all in the z-y plane, and the position adjustment of the optical fiber 8 is completed, enabling the green light emitted by the laser pen 51 to pass through the optical fiber 8 and the differential system 12 and emit from the light outlet 27, and forming a light spot on the baffle at the light outlet 27.

[0068] It should be noted that a fixing rod 97 is fixed to the top of the moving stage 92 by bolts, and a pressure strip 98 is arranged between the fixing rod 97 and the ionization stage 96. The pressure strip 98 presses down on the ionization stage 96 at the bottom, so that the ionization stage 96 moves up and down together with the moving stage 92 during the lifting process.

[0069] It can be understood that a plurality of tension springs 93 are arranged at the bottom of the moving stage 92, and the tension springs 93 are used to pull the moving stage 92 in the direction of the fixed base 91. The second adjusting lead screw 910 is connected to the moving stage 92 through a threaded sleeve, and the threaded sleeve is fixedly installed on the moving stage 92. A plurality of tension springs 93 are also arranged on one side of the ionization stage 96. The tension springs 93 here can eliminate the fitting clearance between the second adjusting lead screw 910 and the threaded sleeve, making the adjustment accuracy of the second adjusting lead screw 910 higher. When the ionization stage 96 needs to be reset or adjusted back, rotate the first adjusting lead screw 99 and the second adjusting lead screw 910 in the reverse direction. Under the pulling action of the tension springs 93, the ionization stage 96 always fits the second adjusting lead screw 910 and moves on the x-y plane, and the ionization stage 96 always fits the moving stage 92 and moves on the y-z plane, enabling the ionization stage 96 to be reset or adjusted back without breaking the vacuum environment of the vacuum cavity 22.

[0070] In addition, three bull's-eye bearings are provided between the side walls of the inner surface of the fixed base 91 and the side walls of the outer surface of the moving table 92, and the bull's-eye bearings are fixed to the fixed base 91. When assembling the fixed base 91 and the moving table 92, the bull's-eye bearings are used for rough positioning in the way that three points determine a plane, and then three setscrews (not shown in the figure) are used to finely adjust the moving table 92 to keep the side walls of the fixed base 91 and the moving table 92 parallel. Correspondingly, three bull's-eye bearings are also provided between the bottom of the inner surface of the moving table 92 and the bottom of the outer surface of the ionization table 96, and the bull's-eye bearings are fixed to the moving table 92. The bull's-eye bearings here can not only be used for positioning, but also reduce the friction between the ionization table 96 and the moving table 92 when the ionization table 96 moves. This is because if the ionization table 96 and the moving table 92 are in surface contact, the contact area is large, resulting in greater friction. By setting the bull's-eye bearings, the ionization table 96 can be changed from surface contact to point contact, and the three-point contact method can effectively reduce the friction, thereby prolonging the service life of the ionization table 96.

[0071] Please refer to Figure 3 、 Figures 5 - 6 、 Figures 9 - 11 As shown, the light source processing chamber 4 is provided with a focusing device 6, and the focusing device 6 is used to inject a red laser beam into the optical fiber 8. The focusing device 6 includes a first electronically controlled femtosecond mirror 61, and a second aperture 62, a half-wave plate 63, a convex lens 64, and a second electronically controlled femtosecond mirror 65 are sequentially arranged in front of the first electronically controlled femtosecond mirror 61 along the long side direction of the light source processing chamber 4. The convex lens 64 is connected to a moving seat, the moving seat is connected to a lead screw, and an adjustment knob 611 is provided at one end of the lead screw. By rotating the adjustment knob 611, the moving seat can be moved, thereby adjusting the position of the convex lens 64 to focus the red laser beam.

[0072] Further, a first femtosecond mirror 66, a wedge prism 67, and a fourth silver-plated mirror 68 are sequentially arranged on one side of the second electronically controlled femtosecond mirror 65 along the short side direction of the light source processing chamber 4. A first CCD camera 69 is arranged on one side of the wedge prism 67 along the long side direction of the light source processing chamber 4, and a second CCD camera 610 is arranged on one side of the fourth silver-plated mirror 68.

[0073] By comparing the pixel points where the light spot is located in the first CCD camera 69 with the pixel points where the light spot is located in the second CCD camera 610, the reflection angles of the first electronically controlled femtosecond mirror 61 and the second electronically controlled femtosecond mirror 65 are adjusted. Specifically, the red laser beam enters from the light inlet 41 opened at the top cover of the light source processing chamber 4, and after being reflected by the first electronically controlled femtosecond mirror 61, it passes through the second aperture 62, the half-wave plate 63, and the convex lens 64, and then is reflected by the second electronically controlled femtosecond mirror 65 and the first femtosecond mirror 66, and exits from the fourth light hole 42 opened in the light source processing chamber 4. The optical switch 71 is turned on, and the red laser beam exiting from the fourth light hole 42 enters the optical switch 71 through the first light hole 28, and after being reflected by the second femtosecond mirror 72, it passes through the third aperture 73 and the incident window 74 and enters the optical fiber 8, and finally passes through the differential system 12 and irradiates on the baffle at the light outlet 27 to form a red light spot. Observe the diameter of the red light spot on the baffle, and adjust the convex lens 64 until the diameter of the red light spot is the smallest, and the focusing is completed. The focusing degree of the red laser beam directly affects the coupling efficiency of the optical fiber 8. When the focus of the red laser beam matches the size of the optical fiber 8, the light energy in the red laser beam can be transmitted to the optical fiber 8 to the maximum extent, reducing losses. If the diameter of the red laser beam incident on the optical fiber 8 exceeds the inner diameter of the optical channel 81 of the optical fiber 8, it is easy to cause part of the light energy to be unable to be effectively coupled into the optical fiber 8. The focusing adjustment can ensure that the focus of the red laser beam is aligned with the optical fiber 8, so that the optical fiber 8 absorbs more light energy, reducing reflection and losses.

[0074] Among them, the first femtosecond mirror 66 will transmit a part of the red laser beam. This part of the red laser beam, as the transmitted beam, will enter the wedge prism 67. A part of the transmitted beam is reflected by the wedge prism 67 to the first CCD camera 69, and another part of the transmitted beam passes through the wedge prism 67 and is reflected by the fourth silver-coated mirror 68 to the second CCD camera 610. At this time, light spots are formed in both the first CCD camera 69 and the second CCD camera 610. There are several grids in both the first CCD camera 69 and the second CCD camera 610. When the pixel points where the light spots are located in the two cameras are at the same position, it means that the optical path of the red laser beam is an ideal path (two points determine a straight line). If the pixel points where the light spots are located in the two cameras are at different positions, the reflection angles of the first electronically controlled femtosecond mirror 61 and the second electronically controlled femtosecond mirror 65 need to be adjusted.

[0075] Please refer to Figures 7 - 18 As shown, an air path device is provided in the extreme ultraviolet light generation chamber 2, and the air path device is used to provide reaction gas to the optical fiber 8. Specifically, the input end of the intake pipeline 111 is connected to an external gas source, and the gas source introduces reaction gas into the intake pipeline 111. According to the required wavelength band of the extreme ultraviolet light, the corresponding reaction gas is selected. The reaction gas includes but is not limited to argon and helium. In this application, the reaction gas is argon.

[0076] The ionization stage 96 is provided with a water inlet channel 961 and a water outlet channel 962. The ionization stage 96 is provided with an air inlet channel 963, and the air inlet channel 963 is not connected to the water inlet channel 961 and the water outlet channel 962. The fiber optic holder fixed on the ionization stage 96 is provided with an air outlet channel 964, and the air inlet channel 963, the air outlet channel 964, and the optical fiber 8 are connected. The optical fiber 8 is provided with an optical channel 81. The optical channel 81 is provided with an air inlet hole 82 opening downward, and the optical channel 81 is provided with an air outlet hole 83 opening upward. The air inlet hole 82 is connected to the air outlet channel 964. Among them, the inner diameter of the optical channel 81 is 0.1 mm - 0.2 mm, the inner diameters of the air inlet hole 82 and the air outlet hole 83 are 0.2 mm - 0.3 mm, and the distance between the air inlet hole 82 and the air outlet hole 83 is 5 mm - 10 mm. In this embodiment, the inner diameter of the optical channel 81 is set to 0.18, the inner diameters of the air inlet hole 82 and the air outlet hole 83 are both set to 0.24, and the distance between the air inlet hole 82 and the air outlet hole 83 is 10 mm.

[0077] In this embodiment, the focusing device 6 cooperates with the gas path device to enable the red laser beam incident into the vacuum chamber 22 to ionize with the reaction gas in the optical fiber 8 to generate extreme ultraviolet light. Specifically, open the main air inlet valve 112 and close the control valve 117, so that the reaction gas enters the ionization stage 96 from the second branch pipe 116. The reaction gas flows through the air inlet channel 963 and the air outlet channel 964, and then enters the optical fiber 8 from the air inlet hole 82. The reaction gas fills the optical channel 81, and the red laser beam is ionized in the optical channel 81 to generate extreme ultraviolet light. The generated extreme ultraviolet light passes through the differential system 12 and enters the transmission chamber 23. The reaction gas is continuously filled into the ionization stage 96, and the gas in the optical fiber 8 is continuously output from the optical channel 81 and the air outlet hole 83 to the vacuum chamber 22. In order to ensure the vacuum degree of the vacuum chamber 22 and the transmission chamber 23, it is necessary to connect a vacuum pump 118 at the first air extraction port 25 and the second air extraction port 26 to continuously pump out the vacuum.

[0078] Since the temperature of the ionization stage 96 will increase when extreme ultraviolet light is generated, the ionization stage 96 needs to be cooled by the cooling system 10. The cooling system 10 includes a water inlet pipeline 101 and a water outlet pipeline 102. The water inlet pipeline 101 is connected to the water inlet channel 961, and the water outlet pipeline 102 is connected to the water outlet channel 962. The water inlet channel 961 and the water outlet channel 962 are connected through a return pipeline 104. External cooling water is continuously injected into the water inlet pipeline 101, and the cooling water flows through the water inlet channel 961 → return pipeline 104 → water outlet channel 962 → water outlet pipeline 102. The return pipeline 104 is made of stainless steel pipe, and the pipeline parts of the water inlet pipeline 101 and the water outlet pipeline 102 located in the vacuum chamber 22 are made of stainless steel bellows. The stainless steel pipe can not only adapt to the vacuum environment to avoid pipeline deformation caused by pressure difference, but also the stainless steel bellows can adapt to the movement of the ionization stage 96. In the vacuum chamber 22, the interfaces of the return pipeline 104, the water inlet pipeline 101, and the water outlet pipeline 102 are all connected to the corresponding components by stainless steel quick connectors and sealing rings, so as to avoid the gasification of the cooling water in the vacuum chamber 22 after leakage, thereby destroying the vacuum degree of the vacuum chamber 22. In addition, a thermocouple 103 is provided in the atmospheric pressure chamber 21. The probe of the thermocouple 103 extends into the vacuum chamber 22 and cooperates with the temperature sensor provided on the ionization stage 96. When the temperature of the ionization stage 96 is higher than the threshold, the optical switch 71 is closed, and at this time, the red laser beam cannot enter the optical fiber 8, playing a role of overheat protection.

[0079] Please refer to Figures 1 - 3 、 Figure 21 As shown, the extreme ultraviolet light generation chamber 2 is connected to the slit adjustment device 13. The slit adjustment device 13 includes two filter glass sheets arranged up and down in the transmission chamber 23, namely the first filter glass sheet 133 and the second filter glass sheet 134. Both filter glass sheets are silver-plated reflectors. The first filter glass sheet 133 and the second filter glass sheet 134 are both arranged at the light outlet 27. The gap between the first filter glass sheet 133 and the second filter glass sheet 134 serves as the slit for passing extreme ultraviolet light. By moving the positions of the first filter glass sheet 133 and the second filter glass sheet 134, the slit can be adjusted to filter out the stray light in the extreme ultraviolet light.

[0080] Specifically, the first filter glass sheet 133 is connected to the second adjustment knob 135 through a lead screw structure. Correspondingly, the second filter glass sheet 134 is also connected to the third adjustment knob 136 through a lead screw structure. Rotating the second adjustment knob 135 can adjust the height of the first filter glass sheet 133, and rotating the third adjustment knob 136 can adjust the height of the second filter glass sheet 134. A third femtosecond mirror 131 is arranged on one side of the two filter glass sheets. The third femtosecond mirror 131 is connected to the first adjustment knob 132 through a rotating shaft. The rotating shaft is installed on the chamber wall of the extreme ultraviolet light generation chamber 2 through a bearing seat. Rotating the first adjustment knob 132 can make the third femtosecond mirror 131 rotate.

[0081] In this embodiment, the first adjustment knob 132 is rotated to make the third femtosecond mirror 131 at a 45° angle. The extreme ultraviolet light entering the transmission cavity 23 is reflected by the third femtosecond mirror 131 and emitted outward from the first observation window 137. A device for detecting the light flux can be connected to the first observation window 137 to detect the light flux of the extreme ultraviolet light. The light flux mainly measures the light transmittance. By measuring the power of the red laser beam light source and the percentage of the power of the extreme ultraviolet light passing through the first observation window 137, the efficiency of the red laser beam generating the extreme ultraviolet light is measured. After detection, the first adjustment knob 132 is rotated again to reset the third femtosecond mirror 131. At this time, the extreme ultraviolet light directly passes through the slit and is emitted from the light outlet 27. During the generation process of the extreme ultraviolet light, some stray light is mixed. Since the wavelength bands of the stray light and the extreme ultraviolet light are different, the slit is adjusted to a width adapted to the wavelength band of the extreme ultraviolet light, so that the stray light is reflected by the first filter glass slide 133 and the second filter glass slide 134 to the second observation window 138, thereby improving the purity of the extreme ultraviolet light.

[0082] The first electronically controlled femtosecond mirror 61, the second electronically controlled femtosecond mirror 65, the first femtosecond mirror 66, the second femtosecond mirror 72, and the third femtosecond mirror 131 are generally referred to as ultrafast mirrors in the common terms of those skilled in the art. An ultrafast mirror is a mirror used to process ultrashort pulsed light (in optics, an ultrashort pulse of light refers to an electromagnetic pulse with a duration on the order of femtoseconds 10 -15 seconds or shorter) signals within a short time. The design requirements of an ultrafast mirror are to be able to withstand a large laser power and efficiently reflect and control light waves on a short time scale.

[0083] In this application, the collimating device 5, the focusing device 6, the optical fiber 8, and the moving device 9 are integrated, and the difficulties in optical path calibration, optical fiber 8 position adjustment, and the cooperation between various devices during the integration process are overcome, making the entire extreme ultraviolet light generator more integrated and smaller in volume, which is beneficial to experimental operation and carrying.

[0084] During use, the collimating device 5 operates, and the green light emitted by it serves as the inspection light. The position of the optical fiber 8 is adjusted through the moving device 9 until the inspection light is coaxial with the optical fiber 8, and a light spot appears on the baffle provided at the light outlet 27, indicating that the optical fiber 8 is collimated. The collimating device 5 is turned off, and the light source processing chamber 4 receives the red laser beam emitted by an external light source. The red laser beam is adjusted in optical path and focused by the focusing device 6 and then enters the optical fiber 8. The vacuum cavity 22 and the transmission cavity 23 are continuously evacuated, the gas path system 11 and the cooling system 10 operate, and the optical fiber 8 continuously receives the reaction gas conveyed by the gas path system 11. The red laser beam and the reaction gas are ionized to generate extreme ultraviolet light. The extreme ultraviolet light generated in the optical fiber 8 is directed towards the light outlet 27, and the slit is adjusted according to the wavelength band of the extreme ultraviolet light. The extreme ultraviolet light passes through the slit and is emitted from the light outlet 27.

[0085] The above has described in detail an embodiment of the present invention, but the content described above is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the application of the present invention should still fall within the scope covered by the claims of the present invention.

Claims

1. A gas path device, suitable for an extreme ultraviolet light generating chamber (2), wherein the extreme ultraviolet light generating chamber (2) is provided with a vacuum cavity (22) and a gas path cavity (24) which are independent of each other, an ionization table (96) is provided in the vacuum cavity (22), and an optical fiber (8) connected thereto is provided on the ionization table (96), characterized in that: The gas path cavity (24) is provided with a gas path system (11), the gas path system (11) comprises an air intake pipeline (111), the end of the air intake pipeline (111) is connected to two branch pipes through a valve, and respectively connects the ionization table (96) and the vacuum cavity (22); Under the action of the pressure difference, the flow direction of the reaction gas in the two branch pipes is adjusted by opening and closing the passage of the branch pipe connected to the vacuum chamber (22).

2. A gas path device according to claim 1, characterized in that: The air intake pipeline (111) is provided with an air intake main valve (112) and a flow regulator (113) along the air flow direction.

3. A gas path device according to claim 1, characterized in that: The branch pipe connected to the ionization table (96) is a second branch pipe (116), and the branch pipe connected to the vacuum chamber (22) is a first branch pipe (115). The output end of the first branch pipe (115) is located in the vacuum chamber (22).

4. A gas path device according to claim 3, characterized in that: The first branch pipe (115) is provided with a control valve (117), and the control valve (117) is used to open and close the passage of the first branch pipe (115).

5. The gas path device according to claim 1, characterized in that: The valve is a three-way valve (114).

6. An extreme ultraviolet light generator, characterized in that: include: An extreme ultraviolet light generating cabin (2), wherein an inspection cabin (3) and a light source processing cabin (4) are suspended on the side wall of the extreme ultraviolet light generating cabin (2); The inspection chamber (3) is provided with a collimating device (5), and the collimating device (5) is used to inject inspection light into the optical fiber (8); the extreme ultraviolet light generating chamber (2) is provided with a light-transmitting device (7) and a moving device (9) for adjusting the position of the optical fiber (8); the collimating device (5) cooperates with the moving device (9) to collimate the optical fiber (8) through the inspection light; The light source processing chamber (4) is provided with a focusing device (6), and the focusing device (6) is used to emit a red laser beam into the optical fiber (8). The extreme ultraviolet light generating chamber (2) is provided with a gas path device as described in any one of claims 1 to 5, and the gas path device is used to provide reaction gas to the optical fiber (8). The focusing device (6) cooperates with the gas path device to enable the red laser beam to ionize with the reaction gas in the optical fiber (8) to generate extreme ultraviolet light.

7. The extreme ultraviolet light generator according to claim 6, characterized in that: Mutually independent cavities are arranged in the extreme ultraviolet light generating chamber (2), the cavities comprising a normal pressure cavity (21), a vacuum cavity (22), a transmission cavity (23), and an air path cavity (24); the transmission cavity (23) is provided with a light outlet (27); and the vacuum cavity (22) and the transmission cavity (23) are both arranged to be in a vacuum environment suitable for the propagation of extreme ultraviolet light.

8. The extreme ultraviolet light generator according to claim 7, characterized in that: The extreme ultraviolet light generating chamber (2) is connected to a slit adjusting device (13), and the slit adjusting device (13) comprises two filter glasses arranged one above the other in the transmission cavity (23), the gap between the two filter glasses serving as a slit for passing the extreme ultraviolet light, and the positions of the two filter glasses are moved to adjust the slit so as to filter stray light in the extreme ultraviolet light.

9. The extreme ultraviolet light generator according to claim 6, characterized in that: The focusing device (6) comprises two CCD cameras, and compares the pixel points where the light spots in the two CCD cameras are located to adjust the reflection angle of the red laser beam.

10. The extreme ultraviolet light generator according to claim 7, characterized in that: The vacuum cavity (22) and the transmission cavity (23) are connected via a differential system (12), and the differential system (12) is used to control the air pressure difference between the two cavities.

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