Optical fiber adjusting structure, extreme ultraviolet light generator applying optical fiber adjusting structure and optical fiber position adjusting method

Abstract

The invention discloses an optical fiber adjusting structure which is suitable for an extreme ultraviolet light generation cabin, the extreme ultraviolet light generation cabin is provided with a vacuum cavity, an optical fiber is arranged in the vacuum cavity, the optical fiber adjusting structure comprises a moving device, the moving device comprises an ionization table, the optical fiber is fixed to the ionization table, and the ionization table is sequentially sleeved with a moving table and a fixed base in the z-axis direction; the fixed base is connected with the vertical adjusting assembly, and the vertical adjusting assembly is used for driving the moving table to twist in the y-z plane so as to adjust the position of the optical fiber in the y-z plane; the moving table is connected with the transverse adjusting assembly, and the transverse adjusting assembly is used for driving the ionization table to twist in the x-y plane so as to adjust the position of the optical fiber in the x-y plane. According to the invention, the vertical adjusting assembly cooperates with the transverse adjusting assembly, and the spatial position of the optical fiber can be adjusted in a vacuum environment, so that the optical fiber can overcome assembly errors and laser beam deviation without breaking the vacuum environment, and is kept coaxial with the laser beam.

Description

Technical Field

[0001] The present invention relates to the technical field of extreme ultraviolet light instruments, and particularly relates to an optical fiber adjustment structure, an extreme ultraviolet light generator to which the optical fiber adjustment structure is applied, and an optical fiber position adjustment method. 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. In an extreme ultraviolet light generator, an optical fiber is an important structure for generating extreme ultraviolet light. Therefore, in order to ensure the smooth generation of extreme ultraviolet light, it is very necessary to keep the channels in the optical fiber coaxial with the infrared laser beam incident on the optical fiber.

[0003] However, in actual operation, due to the alignment error of the optical fiber, the laser beam may deviate from the predetermined axis. This alignment error may come from the slight deviation during the installation and fixation of the optical fiber, resulting in the deviation of the laser beam from its ideal path during transmission. Moreover, the laser beam will diverge to varying degrees during transmission. Especially when the focusing of the laser beam is not ideal, if the output end of the optical fiber is not accurately aligned, or the focal point of the laser beam changes, it may cause the deviation of the laser beam, resulting in the phenomenon of non-coaxiality. In addition, the characteristics of the laser source itself can also affect the stability and direction of the light beam. Each external laser outputs a laser beam with certain polarization characteristics or wavefront distortion, resulting in different degrees of deviation of the laser beam. In addition, the frequency or power fluctuation of the laser source may also cause the instability of the light beam output, making it difficult for the laser beam to be coaxial with the optical fiber. Therefore, due to different objective reasons, it is difficult to take into account various factors during the actual operation process. Summary of the Invention

[0004] The object of the present invention is to solve the problems in the above background art, and to propose an optical fiber adjustment structure, an extreme ultraviolet light generator to which the optical fiber adjustment structure is applied, and an optical fiber position adjustment method.

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

[0006] An optical fiber adjustment structure is applicable to an extreme ultraviolet light generation chamber. The extreme ultraviolet light generation chamber is provided with a vacuum cavity, and an optical fiber is arranged in the vacuum cavity. The structure includes: a moving device, which includes an ionization stage. The optical fiber is fixed to the ionization stage, and a moving stage and a fixed base are sequentially sleeved on the ionization stage along the z-axis direction. The fixed base is connected to a vertical adjustment component, which is used to drive the moving stage to twist in the y-z plane to adjust the position of the optical fiber in the y-z plane. The moving stage is connected to a horizontal adjustment component, which is used to drive the ionization stage to twist in the x-y plane to adjust the position of the optical fiber in the x-y plane. The vertical adjustment component cooperates with the horizontal adjustment component to adjust the spatial position of the optical fiber in the vacuum cavity under a vacuum environment.

[0007] As a further solution of the present invention: The vertical adjustment component includes a rotating block, and a limiting rod is fixedly installed on the moving stage. The rotation of the rotating block is used to drive the limiting rod to move up and down.

[0008] As a further solution of the present invention: The vertical adjustment component further includes a first adjustment screw rod, and the first adjustment screw rod drives the rotation of the rotating block through the telescopic movement at the end.

[0009] As a further solution of the present invention: The horizontal adjustment component includes a second adjustment screw rod. The second adjustment screw rod is connected to the moving stage through a threaded sleeve, and the second adjustment screw rod cooperates with the threaded sleeve to drive the ionization stage to move on the moving stage.

[0010] As a further solution of the present invention: A plurality of tension springs are arranged at the bottom of the moving stage, and the tension springs are used to pull the moving stage in the z direction. A plurality of tension springs are also arranged on one side of the ionization stage, and the tension springs are used to eliminate the cooperation gap between the second adjustment screw rod and the threaded sleeve.

[0011] As a further solution of the present invention: A bull's-eye bearing is arranged between the side wall of the inner surface of the fixed base and the side wall of the outer surface of the moving stage. A setscrew is also arranged on the side wall of the inner surface of the fixed base. The bull's-eye bearing cooperates with the setscrew to position the moving stage. A bull's-eye bearing is also arranged between the bottom of the inner surface of the moving stage and the bottom of the outer surface of the ionization stage.

[0012] As a further solution of the present invention: A waist-shaped hole is opened at the connection between the ionization stage and the second adjustment screw rod, and a contact layer is arranged in the waist-shaped hole. The contact layer is made of stainless steel.

[0013] An extreme ultraviolet light generator comprises: an extreme ultraviolet light generating cabin, an inspection cabin and a light source processing cabin are suspended on the side wall of the extreme ultraviolet light generating cabin; the inspection cabin is provided with a collimating device, the collimating device is used to inject inspection light into an optical fiber, the extreme ultraviolet light generating cabin is provided with a light passing device and an optical fiber adjustment structure, the collimating device cooperates with the optical fiber adjustment structure to collimate the optical fiber through the inspection light; the light source processing cabin is provided with a focusing device, the focusing device is used to inject a red laser beam into the optical fiber, a gas path system is provided in the extreme ultraviolet light generating cabin, the gas path system is used to provide reaction gas to the optical fiber, the focusing device cooperates with the gas path system to ionize the red laser beam with the reaction gas in the optical fiber to generate extreme ultraviolet light.

[0014] As a further solution of the present invention: independent cavities are arranged in the extreme ultraviolet light generating cabin, the cavities include a normal pressure cavity, a vacuum cavity is arranged on one side of the normal pressure cavity, a transmission cavity and an air path cavity located below the transmission cavity are arranged on one side of the vacuum cavity, the transmission cavity has a light outlet, and the vacuum cavity and the transmission cavity are both arranged to be a vacuum environment suitable for the propagation of extreme ultraviolet light.

[0015] A method for adjusting the position of an optical fiber comprises: assembling an optical fiber, fixing the optical fiber on an ionization table in an optical fiber adjustment structure, roughly positioning a moving table through a bull's eye bearing, and then precisely positioning the moving table through a top screw until the moving table is in a parallel state with a fixed base; operating a collimator, the green light emitted by the collimator is used as a test light, and adjusting the position of the optical fiber through the optical fiber adjustment structure; in a vertical adjustment component, two first adjustment screws rotate, the first adjustment screws drive a rotating block to rotate, lift a limit rod, and the limit rod drives the moving table to move up until the central axis of the optical fiber and the central axis of the test light are located in the same plane; in a horizontal adjustment component, two second adjustment screws rotate, the second adjustment screws drive the ionization table to move in the moving table until the test light is coaxial with the optical fiber, a baffle plate arranged at a light outlet presents a light spot, and the position adjustment of the optical fiber is completed.

[0016] Beneficial effects of the present invention:

[0017] (1) In the present invention, the vertical adjustment assembly cooperates with the lateral adjustment assembly to adjust the spatial position of the optical fiber in a vacuum environment, so that the optical fiber can overcome assembly errors and laser beam deviations without breaking the vacuum environment and remain coaxial with the laser beam.

[0018] (2) In the present invention, in the extreme ultraviolet light generator, the optical fiber is collimated and tested by the inspection light emitted by the collimating device, and the position of the optical fiber is adjusted in conjunction with the moving device, which is beneficial to the positioning of the optical fiber.

[0019] (3) In the present invention, the focusing device adjusts the focusing of 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

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 is the front view of the extreme ultraviolet light generator of the present invention;

[0022] Figure 2 is the rear view of the extreme ultraviolet light generator of the present invention;

[0023] Figure 3 is the schematic diagram of the internal structure of the outer shell in the extreme ultraviolet light generator of the present invention;

[0024] Figure 4 is Figure 3 the schematic diagram of the internal structure of the inspection chamber in

[0025] Figure 5 is Figure 3 the schematic diagram of the structure of the light source processing chamber in

[0026] Figure 6 is Figure 5 the schematic diagram of the internal structure of the light source processing chamber in

[0027] Figure 7 is Figure 3 the schematic diagram of the structure of the extreme ultraviolet light generation chamber in

[0028] Figure 8 is Figure 3 the schematic diagram of the structure of the extreme ultraviolet light generation chamber in

[0029] Figure 9 is Figure 7 the schematic diagram of the internal structure of the extreme ultraviolet light generation chamber in

[0030] Figure 10 is Figure 9 the enlarged view of part A in

[0031] Figure 11 is Figure 9 the enlarged view of part B in

[0032] Figure 12 is the schematic diagram of the optical fiber adjustment structure of the present invention;

[0033] Figure 13 is Figure 12 the schematic diagram of the structure of the fixed base in

[0034] Figure 14 isFigure 12 Schematic diagram of the structure of the mobile station;

[0035] Figure 15 is Figure 12 Schematic diagram of the structure of the ionization station;

[0036] Figure 16 is Figure 12 Schematic diagram of the structure of the ionization station;

[0037] Figure 17 is Figure 16 Cross-sectional view of the ionization station;

[0038] Figure 18 is Figure 12 Bottom view of the optical fiber;

[0039] Figure 19 is Figure 12 Top view of the optical fiber;

[0040] Figure 20 Schematic diagram of the structure of the gas path system of the extreme ultraviolet light generator of the present invention;

[0041] Figure 21 is Figure 11 Schematic diagram of the structure of the differential system;

[0042] Figure 22 is Figure 21 Cross-sectional view of the differential system;

[0043] Figure 23 is Figure 7 Schematic diagram of the structure of the slit adjustment device in the transmission cavity.

[0044] In the figure:

[0045] 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 reflector; 54. Second silver-plated reflector; 55. Third silver-plated reflector; 6. Focusing device; 61. First electronically controlled femtosecond reflector; 62. Second diaphragm; 63. Half-wave plate; 64. Convex lens; 65. Second electronically controlled femtosecond reflector; 66. First femtosecond reflector; 67. Wedge prism; 68. Fourth silver-plated reflector; 69. First CCD camera; 610. Second CCD camera; 611. Adjustment knob; 7. Light passing device; 71. Optical switch; 72. Second femtosecond reflector; 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 table; 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; 965. Contact layer; 97. Fixed rod; 98. Pressure strip; 99. First adjustment screw rod; 910. Second adjustment screw rod; 911. Bull's-eye bearing; 912. Set screw; 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 pore; 122. Second pore; 13. Slit adjustment device; 131. Third femtosecond reflector; 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

[0046] 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 making creative efforts shall fall within the protection scope of the present invention.

[0047] Please refer to Figures 7 - 9 , Figure 11As shown in the figure, an optical fiber adjustment structure is applicable to the extreme ultraviolet light generation chamber 2. The extreme ultraviolet light generation chamber 2 is provided with a vacuum cavity 22, and an optical fiber 8 is arranged in the vacuum cavity 22.

[0048] Please refer to Figures 11 - 16 As shown in the figure, the optical fiber adjustment structure includes: a moving device 9. The moving device 9 includes an ionization stage 96. The ionization stage 96 is connected to and fixes an optical fiber holder with the optical fiber 8, so that the optical fiber 8 can be fixed to the ionization stage 96. The ionization stage 96 is successively sleeved with a moving stage 92 and a fixed base 91 along the z-axis direction.

[0049] Among them, three bull's-eye bearings 911 are arranged between the side wall of the inner surface of the fixed base 91 and the side wall of the outer surface of the moving stage 92, and the bull's-eye bearings 911 are fixed to the fixed base 91. Three setscrews 912 are also arranged on the side wall of the inner surface of the fixed base 91. The bull's-eye bearings 911 cooperate with the setscrews 912 to position the moving stage 92. When assembling the fixed base 91 and the moving stage 92, the bull's-eye bearings 911 are used for rough positioning by the way of three points determining a plane, and then the three setscrews 912 are used to finely adjust the moving stage 92 to keep the side wall of the fixed base 91 parallel to the side wall of the moving stage 92. Correspondingly, three bull's-eye bearings 911 are also arranged between the bottom of the inner surface of the moving stage 92 and the bottom of the outer surface of the ionization stage 96, and the bull's-eye bearings 911 are fixed to the moving stage 92. The bull's-eye bearings 911 here can not only be used for positioning, but also reduce the friction between the ionization stage 96 and the moving stage 92 when the ionization stage 96 moves. This is because if the ionization stage 96 and the moving stage 92 are in surface contact, the contact area is large, resulting in greater friction. By setting the bull's-eye bearings 911, the ionization stage 96 can be changed from surface contact to point contact, and the three-point contact method can effectively reduce the friction, thereby improving the service life of the ionization stage 96.

[0050] The fixed base 91 is connected to a vertical adjustment component, and the vertical adjustment component is used to drive the moving stage 92 to twist in the y-z plane to adjust the position of the optical fiber 8 in the y-z plane.

[0051] Specifically, the vertical adjustment component includes a rotating block 95 and a first adjustment screw rod 99. The rotating block 95 is rotatably connected to the fixed base 91 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 stage 92. The rotation of the rotating block 95 is used to drive the limiting rod 94 to move up and down. The first adjustment screw rod 99 drives the rotating block 95 to rotate through the telescopic movement of its end.

[0052] The moving stage 92 is connected to a horizontal adjustment component, and the horizontal adjustment component is used to drive the ionization stage 96 to twist in the x-y plane to adjust the position of the optical fiber 8 in the x-y plane.

[0053] Specifically, the horizontal adjustment assembly includes a second adjustment screw rod 910. The second adjustment screw rod 910 is connected to the moving platform 92 through a threaded sleeve. The threaded sleeve is fixedly installed on the moving platform 92. The second adjustment screw rod 910 cooperates with the threaded sleeve to drive the ionization stage 96 to move on the moving platform 92.

[0054] In this embodiment, the vertical adjustment assembly cooperates with the horizontal adjustment assembly to adjust the spatial position of the optical fiber 8 in the vacuum chamber 22 under a vacuum environment. Specifically, first rotate the two first adjustment screw rods 99 so that the ends of the first adjustment screw rods 99 move towards the rotating block 95. The rotating block 95 rotates and jacks up the limiting rod 94. The limiting rod 94 drives the moving platform 92 to move upward until the central axis of the optical fiber 8 and the central axis of the inspection light (or the incident window 74, because the inspection light needs to enter the vacuum chamber 22 from the incident window 74) are in the same plane (i.e., the x-y plane). Then rotate the two second adjustment screw rods 910 so that the ends of the second adjustment screw rods 910 move towards the ionization stage 96. Under the action of the second adjustment screw rods 910, the ionization stage 96 twists on the x-y plane until the optical fiber 8 is coaxial with the incident window 74, which is convenient for the subsequent red laser beam passing through the incident window 74 to be coaxial with the optical fiber 8, facilitating the generation of 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. The green light emitted by the laser pen 51 passes through the optical fiber 8 and the differential system 12 and exits from the light outlet 27, and forms a light spot on the baffle at the light outlet 27.

[0055] It should be noted that a fixing rod 97 is fixedly installed on the top of the moving platform 92 through bolts. 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 rises and falls together with the moving platform 92 during the lifting process of the moving platform 92.

[0056] In the present invention, a plurality of tension springs 93 are arranged at the bottom of the moving platform 92. The tension springs 93 are used to pull the moving platform 92 in the z direction. Correspondingly, 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 adjustment screw rod 910 and the threaded sleeve, making the adjustment accuracy of the second adjustment screw rod 910 higher. During the process of adjusting the position of the optical fiber 8, when the ionization stage 96 needs to be reset or retracted, reverse-rotate the first adjustment screw rod 99 and the second adjustment screw rod 910. Under the pulling action of the tension springs 93, the ionization stage 96 always fits against the second adjustment screw rod 910 and moves on the x-y plane, and the ionization stage 96 always fits against the moving platform 92 and moves on the y-z plane, enabling the ionization stage 96 to be reset or retracted without breaking the vacuum environment of the vacuum chamber 22.

[0057] In some embodiments, a waist-shaped hole is formed at the connection between the ionization stage 96 and the second adjusting screw rod 910. A contact layer 965 is arranged in the waist-shaped hole, and the contact layer 965 is made of stainless steel. When the second adjusting screw rod 910 is rotated, the end of the second adjusting screw rod 910 pushes the contact layer 965, and the ionization stage 96 moves. At this time, the contact layer 965 isolates the side wall of the ionization stage 96 from the end of the second adjusting screw rod 910, so that the end of the second adjusting screw rod 910 cannot directly contact the ionization stage 96, but can still drive the ionization stage 96 to move. Since the end of the second adjusting screw rod 910 directly contacts the ionization stage 96 made of aluminum or aluminum alloy, it is easy to cause significant wear on the ionization stage 96. The arrangement of the contact layer 965 can provide a transition, thereby effectively reducing the deformation degree of the ionization stage 96 and improving the service life of the ionization stage 96. The contact layer 965 with higher strength is also not easily deformed, making the adjustment of the second adjusting screw rod 910 not easily fail, and thus maintaining a high adjustment accuracy.

[0058] In the present application, even if there is an alignment error in the optical fiber 8, the position of the optical fiber 8 can be adjusted in real time by the moving device 9, so that the laser beam is not easily deviated and can be better coupled with the optical fiber. Although the characteristics of the laser source itself will also affect the stability and direction of the light beam, each externally emitted laser beam has certain polarization characteristics or wavefront distortions, resulting in different degrees of deviation of the laser beam. However, by adjusting the position of the optical fiber 8 by the moving device 9, the optical fiber 8 can be position-matched for the deviation of the laser beam, solving the phenomenon that the optical fiber 8 and the laser beam are not coaxial due to the objective factors of the laser source. In addition, fluctuations in the frequency or power of the laser source will also cause instability in the output of the light beam, making it difficult for the laser beam to remain coaxial with the optical fiber 8. For such fluctuations, the optical fiber 8 is adjusted in real time by the moving device 9 to adapt, so as to achieve the coaxiality of the optical fiber 8 and the laser beam.

[0059] Please refer to Figures 1 - 3 As shown in the figure, the present invention is an extreme ultraviolet light generator, including: an extreme ultraviolet light generation chamber 2, and an inspection chamber 3 and a light source processing chamber 4 are 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, so 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 arranged 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 arranged 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.

[0060] Please refer to Figures 7 - 8As shown, multiple independent cavities are provided in the extreme ultraviolet light generation chamber 2. The cavity includes an atmospheric pressure cavity 21. A vacuum cavity 22 is 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 to facilitate observing the generation of extreme ultraviolet light inside. A transmission cavity 23 and a gas path cavity 24 located below the transmission cavity 23 are provided on one side of the vacuum cavity 22. An optical output port 27 is opened in the transmission cavity 23.

[0061] Among them, please refer to Figure 9 , Figure 11 , Figures 21 - 22 As shown, both the vacuum cavity 22 and the transmission cavity 23 are set to a vacuum environment suitable 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, which is convenient for the transmission of extreme ultraviolet light.

[0062] 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 air inlet end of the first channel 121 is equal to the inner diameter of the air 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 that the optical path of the extreme ultraviolet light cannot pass through due to an angular deviation during the installation of the differential system 12.

[0063] Please refer to Figure 4 , Figure 7 As shown, 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. The laser pen 51 can emit green light, and the green light is used as the inspection light. 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 at the output end of the laser pen 51 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 optical hole 31 opened in the inspection chamber 3 and the second optical hole 29 opened in the extreme ultraviolet light generation chamber 2.

[0064] Please refer to Figures 7 - 10As shown in the figure, the extreme ultraviolet light generation chamber 2 is provided with a light passing device 7 and an optical fiber adjustment structure. 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. A third diaphragm 73 and an incident window 74 are arranged along the green light transmission direction on the second femtosecond mirror 72. The window piece on the incident window 74 is coated with an infrared antireflection film.

[0065] When the collimation device 5 is in operation, 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 entering 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.

[0066] Please refer to Figures 7 - 12 As shown in the figure, the collimation device 5 cooperates with the optical fiber adjustment structure to collimate the optical fiber 8 through the inspection light.

[0067] In this embodiment, when collimating or correcting the position of the optical fiber 8, rotate the two first adjustment lead screws 99 so that the ends of the first adjustment lead screws 99 move towards the rotating block 95. The rotating block 95 rotates and jacks up the limiting rod 94. The limiting rod 94 drives the moving table 92 to move up until the central axes 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 adjustment lead screws 910 so that the ends of the second adjustment lead screws 910 move towards the ionization stage 96. Under the action of the second adjustment lead screws 910, the ionization stage 96 twists on the x-y plane until the optical fiber 8 is coaxial with the incident window 74, which is convenient for 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, so that the green light emitted by the laser pen 51 passes through the optical fiber 8 and the differential system 12 and exits from the light outlet 27, and a light spot is formed on the baffle at the light outlet 27.

[0068] Please refer to Figure 3 、 Figures 5 - 6 、 Figures 9 - 11As shown in the figure, a focusing device 6 is provided in the light source processing chamber 4. 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. Along the long side direction of the light source processing chamber 4, 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. 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. The laser beam will diverge to varying degrees during transmission. Especially when the focusing of the laser beam is not ideal enough, by focusing the red laser beam through the focusing device 6 and then cooperating with the moving device 9 to align and position the optical fiber 8, the alignment between the optical fiber 8 and the red laser beam can be made more precise, the red laser beam is not easy to deviate, and it is convenient for the red laser beam to be coaxial with the optical fiber 8.

[0069] 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.

[0070] 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, is reflected by the first electronically controlled femtosecond mirror 61, passes through the second aperture 62, the half-wave plate 63, and the convex lens 64, and is then reflected by the second electronically controlled femtosecond mirror 65 and the first femtosecond mirror 66, and is emitted from the fourth light hole 42 opened in the light source processing chamber 4. The light switch 71 is turned on, and the red laser beam emitted from the fourth light hole 42 enters the light switch 71 through the first light hole 28, is reflected by the second femtosecond mirror 72, passes through the third aperture 73 and the incident window 74 to enter 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, 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 greatest extent, reducing losses. If the diameter of the red laser beam injected into the optical fiber 8 exceeds the inner diameter of the optical channel 81 of the optical fiber 8, it is easy to cause some 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.

[0071] Among them, a part of the red laser beam will pass through the first femtosecond mirror 66. This part of the red laser beam, as a 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.

[0072] Please refer to Figures 7 - 20 As shown, an air path system 11 is provided in the extreme ultraviolet light generation chamber 2. The air path system 11 is used to provide reaction gas to the optical fiber 8. The air path system 11 includes an intake pipeline 111. 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. An intake main valve 112 and a flow regulator 113 are arranged on the intake pipeline 111 along the gas flow direction. A three-way valve 114 is arranged at the end of the intake pipeline 111. The three-way valve 114 is connected to two branch pipes, which are the first branch pipe 115 and the second branch pipe 116 respectively. The output end of the first branch pipe 115 is located in the vacuum cavity 22, and the second branch pipe 116 is communicated with the ionization stage 96.

[0073] 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. The air inlet channel 963 is not communicated with the water inlet channel 961 and the water outlet channel 962. An air outlet channel 964 is provided on the optical fiber holder fixed on the ionization stage 96. The air inlet channel 963, the air outlet channel 964, and the optical fiber 8 are connected and arranged. 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 air inlet hole 82 is communicated with the air outlet channel 964.

[0074] In this embodiment, the focusing device 6 cooperates with the gas path system 11 to cause the red laser beam incident on the vacuum chamber 22 to ionize with the reaction gas in the optical fiber 8 to generate extreme ultraviolet light. Specifically, the main intake valve 112 is opened and the control valve 117 is closed, so that the reaction gas enters the ionization stage 96 from the second branch pipe 116. The reaction gas flows through the intake passage 963 and the outlet passage 964, and then enters the optical fiber 8 through the intake 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 extract vacuum.

[0075] It can be understood that when the reaction gas needs to be replaced, the gas in the vacuum chamber 22 and the transmission chamber 23 needs to be extracted completely before introducing the new gas. When replacing the gas, the main intake valve 112 is closed. Since the inner diameters of the optical channel 81, the intake hole 82, and the air outlet hole 83 are small, it is difficult to quickly exhaust the reaction gas remaining in the intake pipeline 111 and the second branch pipe 116. At this time, the control valve 117 needs to be opened. The first branch pipe 115 connected to the vacuum chamber 22 is provided, and the reaction gas in the intake pipeline 111 and the second branch pipe 116 can be directly introduced into the first branch pipe 115 when the vacuum pump 118 extracts air. The reaction gas flows from the first branch pipe 115 into the vacuum chamber 22 and can be quickly extracted by the vacuum pump 118.

[0076] Since the temperature of the ionization stage 96 will increase when extreme ultraviolet light is generated, it is necessary to cool down the ionization stage 96 through 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. Moreover, 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 → the return pipeline 104 → the water outlet channel 962 → the 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 deformation of the pipeline due to 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 cooling water from vaporizing in the vacuum chamber 22 after leakage, thereby destroying the vacuum degree of the vacuum chamber 22. In addition, a thermocouple 103 is arranged in the atmospheric pressure chamber 21. The probe of the thermocouple 103 extends into the vacuum chamber 22 and cooperates with the temperature sensor arranged on the ionization stage 96. When the temperature of the ionization stage 96 is higher than the threshold value, 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.

[0077] Please refer to Figures 1 - 3 、 Figure 23 As shown in the figure, 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 the 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.

[0078] Specifically, the first filter glass sheet 133 is connected to the second adjustment knob 135 through a screw rod structure. Correspondingly, the second filter glass sheet 134 is also connected to the third adjustment knob 136 through a screw rod 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.

[0079] In this embodiment, rotate the first adjustment knob 132 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 at 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, rotate the first adjustment knob 132 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.

[0080] The first electrically controlled femtosecond mirror 61, the second electrically 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 in 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.

[0081] 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 portability.

[0082] In another embodiment, a method for adjusting the position of an optical fiber includes:

[0083] Assemble the optical fiber 8, fix the optical fiber 8 on the ionization stage 96 in the optical fiber adjustment structure, roughly position the moving stage 92 through the bull's-eye bearing 911, and then precisely position the moving stage 92 through the setscrew 912 until the moving stage 92 is parallel to the fixed base 91.

[0084] The collimating device 5 operates, and the green light emitted by it is used as the inspection light to adjust the position of the optical fiber 8 through the optical fiber adjustment structure.

[0085] In the vertical adjustment assembly, two first adjustment lead screws 99 rotate. The first adjustment lead screws 99 drive the rotation block 95 to rotate, jack up the limit rod 94, and the limit rod 94 drives the moving platform 92 to move upward until the central axis of the optical fiber 8 and the central axis of the inspection light are in the same plane.

[0086] In the horizontal adjustment assembly, two second adjustment lead screws 910 rotate. The second adjustment lead screws 910 drive the ionization stage 96 to move within the moving platform 92 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, and the position adjustment of the optical fiber 8 is completed.

[0087] Specifically, the steps are as follows:

[0088] S1. Assemble the optical fiber 8, fix the optical fiber 8 on the ionization stage 96 in the optical fiber adjustment structure, roughly position the moving platform 92 through the bull's-eye bearing 911, and then precisely position the moving platform 92 through the setscrew 912 until the moving platform 92 is parallel to the fixed base 91.

[0089] S2. The collimation device 5 operates, and the green light emitted by it serves as the inspection light, and the position of the optical fiber 8 is adjusted through the optical fiber adjustment structure.

[0090] Specifically, remove the second femtosecond mirror 72, so that the green light emitted by the laser pen 51 passes through the third aperture 73 and the incident window 74 and enters the vacuum chamber 22. And place a baffle at the light outlet 27 and observe whether a green light spot appears on the baffle. If a green light spot appears on the baffle, the position of the optical fiber 8 is in the ideal position, skip S3 and S4, and perform the subsequent extreme ultraviolet light generation operation. If no green light spot appears on the baffle, the position of the optical fiber 8 needs to be adjusted.

[0091] S3. In the vertical adjustment assembly, two first adjustment lead screws 99 rotate. The first adjustment lead screws 99 drive the rotation block 95 to rotate, jack up the limit rod 94, and the limit rod 94 drives the moving platform 92 to move upward until the central axis of the optical fiber 8 and the central axis of the inspection light are in the same plane.

[0092] Specifically, rotate the two first adjustment lead screws 99 so that the ends of the first adjustment lead screws 99 move toward the rotation block 95 direction. The rotation block 95 rotates and jacks up the limit rod 94, and the limit rod 94 drives the moving platform 92 to move upward until the central axes of the optical fiber 8 and the incident window 74 are in the x - y plane.

[0093] S4. In the horizontal adjustment assembly, two second adjustment lead screws 910 rotate. The second adjustment lead screws 910 drive the ionization stage 96 to move within the moving platform 92 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, and the position adjustment of the optical fiber 8 is completed.

[0094] Specifically, the two second adjusting screws 910 are rotated to move the ends of the second adjusting screws 910 toward the ionization stage 96. Under the action of the second adjusting screws 910, the ionization stage 96 twists in the xy plane until the inspection light passes through the optical fiber 8 to form a light spot on the baffle, indicating that the optical fiber 8 is coaxial with the incident window 74. At this time, the central axis of the incident window 74, the central axis of the optical fiber 8, and the central axis of the differential system 12 are all located in the zy plane, and the position adjustment of the optical fiber 8 is completed.

[0095] If no light spot appears on the baffle at all, it is necessary to return to S3 and readjust the optical fiber 8.

[0096] In one embodiment, the steps of generating extreme ultraviolet light using an extreme ultraviolet light generator are as follows:

[0097] S1. The collimating device 5 is in operation, and the green light it emits is used as the test light. The position of the optical fiber 8 is adjusted by the moving device 9 until the test light is coaxial with the optical fiber 8, and the baffle plate set at the light outlet 27 shows a light spot, and the collimation of the optical fiber 8 is completed.

[0098] Specifically, the second femtosecond reflector 72 is removed, so that the green light emitted by the laser pen 51 passes through the third aperture 73 and the incident window 74 and enters the vacuum chamber 22. A baffle is placed at the light outlet 27 to observe whether a green light spot appears on the baffle.

[0099] If no green light spot appears on the baffle, the position of the optical fiber 8 needs to be adjusted. First, rotate the two first adjustment screws 99 to move the end of the first adjustment screw 99 toward the rotating block 95. The rotating block 95 rotates and lifts the limit rod 94. The limit rod 94 drives the moving platform 92 to move up until the central axis of the optical fiber 8 and the incident window 74 is located in the xy plane. Then rotate the two second adjustment screws 910 to move the end of the second adjustment screw 910 toward the ionization table 96. Under the action of the second adjustment screw 910, the ionization table 96 twists in the xy plane until the optical fiber 8 is coaxial with the incident window 74. At this time, the central axis of the incident window 74, the central axis of the optical fiber 8, and the central axis of the differential system 12 are all located in the zy plane, and the position of the optical fiber 8 is adjusted. The green light emitted by the laser pen 51 passes through the optical fiber 8 and the differential system 12, and is emitted from the light outlet 27, and forms a light spot on the baffle at the light outlet 27, and the alignment of the optical fiber 8 is completed.

[0100] S2, the collimator 5 is turned off, and the green light disappears. The light source processing chamber 4 receives the red laser beam emitted by the external light source, and the red laser beam is adjusted by the focusing device 6 and focused before being emitted into the optical fiber 8.

[0101] Specifically, the red laser beam enters through the light inlet 41 opened at the top cover of the light source processing chamber 4. After being reflected by the first electronically controlled femtosecond mirror 61, it passes through the second aperture 62, half-wave plate 63, and convex lens 64, and is then reflected by the second electronically controlled femtosecond mirror 65 and the first femtosecond mirror 66, and exits through the fourth light hole 42 opened in the light source processing chamber 4. When the optical switch 71 is turned on, the red laser beam exiting through 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 minimized, and the focusing is completed.

[0102] If no red light spot appears on the baffle, the optical path of the red laser beam needs to be adjusted. Since 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-plated 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 in the same grid position, it means that the optical path of the red laser beam is the ideal path (two points determine a straight line). If the pixel points where the light spots are located in the two cameras are in different grid positions, the optical path of the red laser beam needs to be adjusted.

[0103] The way to adjust the optical path of the red laser beam is as follows: preset a standard pixel point, compare the pixel point where the light spot is located in the first CCD camera 69 with the pixel point where the light spot is located in the second CCD camera 610, and adjust the reflection angles of the first electronically controlled femtosecond mirror 61 and the second electronically controlled femtosecond mirror 65 so that the pixel point positions where the two light spots are located are at the standard pixel point. Two points determine a straight line. When the pixel point positions where the two light spots are located are the same, it means that the red laser beam entering the optical fiber 8 is coaxial with the optical fiber 8.

[0104] S3. The vacuum cavity 22 and the transmission cavity 23 are continuously evacuated, the gas path system 11 and the cooling system 10 are operating, the optical fiber 8 continuously receives argon gas transported by the gas path system 11, and the red laser beam and the reaction gas are ionized to generate extreme ultraviolet light.

[0105] Specifically, a vacuum pump 118 is connected to the first air extraction port 25 and the second air extraction port 26 to continuously evacuate. The main air inlet valve 112 is opened, and the control valve 117 is closed, so that argon gas enters the ionization stage 96 from the second branch pipe 116, and the argon 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, and the argon 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 enters the transmission cavity 23 through the differential system 12.

[0106] During the generation of extreme ultraviolet light, the ionization table 96 needs to be cooled to prevent the temperature from affecting the generation of extreme ultraviolet light. Cooling water is continuously injected into the water inlet pipe 101 through an external water source, and the cooling water flows through the water inlet channel 961 → the return pipe 104 → the water outlet channel 962 → the water outlet pipe 102, thereby taking away the heat of the ionization table 96.

[0107] S4. The extreme ultraviolet light generated in the optical fiber 8 is emitted toward the light outlet 27. The slit is adjusted according to the wavelength band of the extreme ultraviolet light, and the extreme ultraviolet light is emitted from the light outlet 27 through the slit.

[0108] The first adjustment knob 132 is turned to make the third femtosecond reflector 131 at a 45° angle, and the extreme ultraviolet light entering the transmission cavity 23 is reflected by the third femtosecond reflector 131 and emitted from the first observation window 137. A device for detecting the light flux is connected to the first observation window 137 to detect the light flux of the extreme ultraviolet light. After the detection, the first adjustment knob 132 is turned to reset the third femtosecond reflector 131. At this time, the extreme ultraviolet light directly passes through the slit and is emitted from the light outlet 27.

[0109] Since some stray light is mixed in the process of generating extreme ultraviolet light, and the wavelength band of the stray light is different from that of the extreme ultraviolet light, the slit is adjusted to a width suitable for the wavelength band of the extreme ultraviolet light so that the stray light is reflected by the first filter glass 133 and the second filter glass 134 to the second observation window 138 .

[0110] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. An optical fiber adjustment structure, applicable to an extreme ultraviolet light generating chamber (2), wherein the extreme ultraviolet light generating chamber (2) is provided with a vacuum cavity (22), and an optical fiber (8) is provided in the vacuum cavity (22), characterized in that: include: A moving device (9), the moving device (9) comprising an ionization table (96), the optical fiber (8) being fixed to the ionization table (96), the ionization table (96) being provided with a moving table (92) and a fixed base (91) in sequence along the z-axis direction; The fixed base (91) is connected to a vertical adjustment component, and the vertical adjustment component is used to drive the movable platform (92) to twist in the yz plane to adjust the position of the optical fiber (8) in the yz plane; The movable platform (92) is connected to a transverse adjustment component, and the transverse adjustment component is used to drive the ionization platform (96) to twist in the xy plane to adjust the position of the optical fiber (8) in the xy plane; The vertical adjustment component cooperates with the lateral adjustment component to adjust the spatial position of the optical fiber (8) in the vacuum cavity (22) under a vacuum environment.

2. The optical fiber adjustment structure according to claim 1, characterized in that: The vertical adjustment assembly comprises a rotating block (95), a limiting rod (94) is fixedly mounted on the moving platform (92), and the rotating block (95) is rotated to drive the limiting rod (94) to rise and fall.

3. The optical fiber adjustment structure according to claim 2, characterized in that: The vertical adjustment assembly further comprises a first adjustment screw rod (99), and the first adjustment screw rod (99) drives the rotating block (95) to rotate by extending and retracting the end portion thereof.

4. The optical fiber adjustment structure according to claim 1, characterized in that: The lateral adjustment assembly comprises a second adjustment screw (910), the second adjustment screw (910) being connected to the movable platform (92) via a threaded sleeve, and the second adjustment screw (910) cooperating with the threaded sleeve to drive the ionization platform (96) to move on the movable platform (92).

5. The optical fiber adjustment structure according to claim 4, characterized in that: A plurality of tension springs (93) are arranged at the bottom of the movable platform (92), and the tension springs (93) are used to pull the movable platform (92) in the z direction; A plurality of tension springs (93) are also arranged on one side of the ionization table (96), and the tension springs (93) are used to eliminate the matching clearance between the second adjusting screw rod (910) and the threaded sleeve.

6. The optical fiber adjustment structure according to claim 1, characterized in that: A bull's eye bearing (911) is arranged between the side wall of the inner surface of the fixed base (91) and the side wall of the outer surface of the movable platform (92); a top screw (912) is also arranged on the side wall of the inner surface of the fixed base (91); the bull's eye bearing (911) cooperates with the top screw (912) to position the movable platform (92); A bull's eye bearing (911) is also provided between the bottom of the inner surface of the moving platform (92) and the bottom of the outer surface of the ionization platform (96).

7. The optical fiber adjustment structure according to claim 5, characterized in that: A waist hole is provided at the connection between the ionization table (96) and the second adjusting screw rod (910), and a contact layer (965) is arranged in the waist hole. The contact layer (965) is made of stainless steel.

8. 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-passing device (7) and an optical fiber adjustment structure according to any one of claims 1 to 7, and the collimating device (5) cooperates with the optical fiber adjustment structure 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 inject a red laser beam into the optical fiber (8). The extreme ultraviolet light generating chamber (2) is provided with a gas path system (11), and the gas path system (11) is used to provide reaction gas to the optical fiber (8). The focusing device (6) cooperates with the gas path system (11) to enable the red laser beam to ionize with the reaction gas in the optical fiber (8) to generate extreme ultraviolet light.

9. The extreme ultraviolet light generator according to claim 8, 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.

10. A method for adjusting the position of an optical fiber, characterized in that: include: Assembling the optical fiber (8), fixing the optical fiber (8) on the ionization table (96) in the optical fiber adjustment structure according to any one of claims 1 to 7, roughly positioning the movable table (92) by means of a bull's eye bearing (911), and then precisely positioning the movable table (92) by means of a top screw (912), until the movable table (92) is in a parallel state with the fixed base (91); The collimator (5) is in operation, and the green light emitted by the collimator is used as the inspection light, and the position of the optical fiber (8) is adjusted through the optical fiber adjustment structure; In the vertical adjustment assembly, two first adjustment screws (99) rotate, the first adjustment screws (99) drive the rotating block (95) to rotate, lift the limit rod (94), and the limit rod (94) drives the moving platform (92) to move upward until the central axis of the optical fiber (8) and the central axis of the inspection light are located in the same plane; In the lateral adjustment assembly, the two second adjustment screws (910) rotate, and the second adjustment screws (910) drive the ionization table (96) to move in the moving table (92) until the inspection light is coaxial with the optical fiber (8), and the baffle plate set at the light outlet (27) shows a light spot, and the position adjustment of the optical fiber (8) is completed.

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