Extreme ultraviolet light generator and use method thereof

Abstract

The extreme ultraviolet light generator comprises an extreme ultraviolet light generation cabin, an inspection cabin and a light source processing cabin are installed on the side wall of the extreme ultraviolet light generation cabin in a suspended mode, the inspection cabin is provided with a collimation device, the collimation device is used for emitting inspection light to an optical fiber, and the extreme ultraviolet light generation cabin is provided with a light passing device and a moving device for adjusting the position of the optical fiber. The optical fiber is collimated through inspection light, the light source processing cabin is provided with a focusing device, the focusing device is used for emitting a red laser beam to the optical fiber, a gas path system is arranged in the extreme ultraviolet light generation cabin, and the focusing device is matched with the gas path system, so that the red laser beam is ionized with reaction gas in the optical fiber to generate extreme ultraviolet light. According to the invention, the collimation device, the focusing device, the optical fiber and the mobile device are integrated, and the difficulty in optical path calibration, optical fiber position adjustment and cooperation among the devices in the integration process is overcome, so that the whole extreme ultraviolet light generator is more integrated, smaller in size and beneficial to experimental operation and carrying.

Description

Technical Field

[0001] The present invention relates to the technical field of extreme ultraviolet light instruments, and in particular to an extreme ultraviolet light generator and a method for using the same. Background Art

[0002] Extreme ultraviolet light, also known as extreme ultraviolet radiation, refers to electromagnetic radiation with a wavelength ranging from 121 nanometers to 10 nanometers in the electromagnetic spectrum. Extreme ultraviolet light is often used in photolithography. During the generation of extreme ultraviolet light, a focusing mirror device is required to focus the incident red laser beam to achieve the smallest spot of the red laser beam injected into the optical fiber. And because the inner diameter of the optical channel in the optical fiber is very small, it is difficult to align the red laser beam injected into the optical fiber with the optical fiber. It is necessary to connect an additional collimation device to detect the position of the optical fiber to facilitate the correction of the optical fiber position.

[0003] When generating extreme ultraviolet light, these focusing mirror devices, collimation devices and extreme ultraviolet light generators are all independently operated devices, occupying a large space, which is not conducive to experimental operation and equipment carrying. Summary of the invention

[0004] The purpose of the present invention is to solve the problem in the prior art that the focusing mirror device, the collimating device and the extreme ultraviolet light generator are all independently operated devices, occupying a large space, which is not conducive to experimental operation and equipment carrying, and to propose an extreme ultraviolet light generator and a method for using the same.

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

[0006] An extreme ultraviolet light generator, comprising:

[0007] An extreme ultraviolet light generating cabin, wherein an inspection cabin and a light source processing cabin are suspended on the side wall of the extreme ultraviolet light generating cabin;

[0008] The inspection cabin is provided with a collimating device, and the collimating device is used to inject inspection light into the optical fiber. The extreme ultraviolet light generating cabin is provided with a light-passing device and a moving device for adjusting the position of the optical fiber. The collimating device cooperates with the moving device to collimate the optical fiber through the inspection light.

[0009] The light source processing chamber is provided with a focusing device for injecting a red laser beam into the optical fiber. The extreme ultraviolet light generating chamber is provided with a gas path system for providing reaction gas to the optical fiber. The focusing device cooperates with the gas path system to enable the red laser beam to ionize with the reaction gas in the optical fiber to generate extreme ultraviolet light.

[0010] As a further solution of the present invention: independent cavities are arranged in the extreme ultraviolet light generating chamber, and the cavities include a normal pressure cavity, a vacuum cavity, a transmission cavity, and a gas path cavity, and the transmission cavity has a light outlet.

[0011] As a further solution of the present invention: the extreme ultraviolet light generating cabin is connected to a slit adjusting device, and the slit adjusting device is provided with a slit with adjustable width, and the slit is used to filter stray light in the extreme ultraviolet light.

[0012] As a further solution of the present invention: the focusing device includes two CCD cameras, and the pixel points where the light spots in the two CCD cameras are located are compared to adjust the reflection angle of the red laser beam.

[0013] As a further solution of the present invention: the moving device includes a fixed base, the fixed base is fixedly installed on the vacuum chamber, a moving platform that can swing on the yz plane is arranged above the fixed base, an ionization table that can twist on the xy plane is arranged in the moving platform, and the ionization table is connected to the optical fiber rack on which the optical fiber is fixed.

[0014] As a further solution of the present invention: a plurality of tension springs are arranged at the bottom of the movable platform, and the tension springs are used to pull the movable platform in the direction of the fixed base.

[0015] As a further solution of the present invention: the movable platform is provided with a threaded sleeve, and a plurality of tension springs are also provided on one side of the ionization platform, and the tension springs are used to eliminate the matching clearance generated by the threaded sleeve during operation.

[0016] As a further solution of the present invention: the optical fiber defines an optical channel, the optical channel defines an air inlet downward, the optical channel defines an air outlet upward, and the air inlet is connected to the ionization table.

[0017] As a further solution of the present invention: the vacuum cavity and the transmission cavity are connected via a differential system, and the differential system is used to control the air pressure difference between the two cavities.

[0018] A method of using an extreme ultraviolet light generator, comprising:

[0019] The collimation device is running, and the green light it emits is used as the inspection light. The position of the optical fiber is adjusted by the moving device until the inspection light is coaxial with the optical fiber, and the baffle set at the light outlet shows a light spot, and the optical fiber alignment is completed;

[0020] The collimation device is closed, and the light source processing cabin receives the red laser beam emitted by the external light source. The red laser beam is adjusted in light path and focused by the focusing device before being emitted into the optical fiber.

[0021] The vacuum chamber and the transmission chamber are continuously evacuated, the gas system and the cooling system are in operation, the optical fiber continuously receives the reaction gas transported by the gas system, and the red laser beam ionizes with the reaction gas to generate extreme ultraviolet light;

[0022] The extreme ultraviolet light generated in the optical fiber is emitted toward the light outlet, 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 through the slit.

[0023] Beneficial effects of the present invention:

[0024] (1) In the present invention, the collimating device, focusing device, optical fiber, and moving device are integrated, and the difficulties in optical path calibration, optical fiber position adjustment, and coordination between various devices during the integration process are overcome, so that the entire extreme ultraviolet light generator is more integrated and smaller in size, which is conducive to experimental operation and carrying.

[0025] (2) In the present invention, the optical fiber is aligned and tested by using 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.

[0026] (3) In the present invention, after the adjustment device adjusts the position of the optical fiber, it can ensure that the red laser beam is coaxial with the optical fiber, which is beneficial to the generation of extreme ultraviolet light.

[0027] (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.

[0028] (5) In the present invention, the extreme ultraviolet light is filtered by the slit adjustment device, which is beneficial to improving the purity of the extreme ultraviolet light. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] Figure 1 is a front view of the extreme ultraviolet light generator of the present invention;

[0031] Figure 2 is a rear view of the extreme ultraviolet light generator of the present invention;

[0032] Figure 3 It is a schematic diagram of the internal structure of the housing of the extreme ultraviolet light generator of the present invention;

[0033] Figure 4 yes Figure 3 Schematic diagram of the internal structure of the middle inspection cabin;

[0034] Figure 5 yes Figure 3 Schematic diagram of the structure of the central light source processing cabin;

[0035] Figure 6 yes Figure 5 Schematic diagram of the internal structure of the central light source processing cabin;

[0036] Figure 7 yes Figure 3 Schematic diagram of the structure of the extreme ultraviolet light generating cabin;

[0037] Figure 8 yes Figure 3 Schematic diagram of the structure of the extreme ultraviolet light generating cabin;

[0038] Fig. 9 yes Figure 7 Schematic diagram of the internal structure of the extreme ultraviolet light generating cabin;

[0039] Fig.10 yes Fig. 9 The enlarged view of point A in the middle;

[0040] Fig.11 yes Fig. 9 The enlarged view of point B in the middle;

[0041] Fig.12 yes Fig. 9 The structural diagram of the middle regulating device;

[0042] Fig.13 yes Fig.12 Schematic diagram of the structure of the medium ionization station;

[0043] Fig.14 yes Fig.13 A cross-sectional view of the central ionization station;

[0044] Fig.15 yes Fig.12 Bottom view of the optical fiber;

[0045] Fig.16 yes Fig.12 A top view of the optical fiber;

[0046] Fig.17 It is a structural schematic diagram of the gas path system of the extreme ultraviolet light generator of the present invention;

[0047] Fig.18 yes Fig.11 Schematic diagram of the structure of the medium differential system;

[0048] Fig.19 yes Fig.18 Cross-sectional view of the differential system;

[0049] Fig. 20 yes Figure 7 A schematic diagram of the structure of the slit adjustment device in the transmission cavity;

[0050] Fig.21 It is a schematic flow chart of the method for using the extreme ultraviolet light generator of the present invention.

[0051] In the figure:

[0052] 1. Shell; 2. Extreme ultraviolet light generating chamber; 21. Normal pressure chamber; 22. Vacuum chamber; 23. Transmission chamber; 24. Gas path chamber; 25. First air extraction port; 26. Second air extraction port; 27. Light outlet; 28. First light hole; 29. ​​Second light hole; 3. Inspection chamber; 31. Third light hole; 4. Light source processing chamber; 41. Light inlet; 42. Fourth light hole; 5. Collimation device; 51. Laser pen; 52. First aperture; 53. First silver-coated reflector; 54. Second silver-coated reflector; 55. Third silver-coated reflector; 6. , focusing device; 61, first electrically controlled femtosecond reflector; 62, second aperture; 63, half-wave plate; 64, convex lens; 65, second electrically controlled femtosecond reflector; 66, first femtosecond reflector; 67, wedge prism; 68, fourth silver-coated reflector; 69, first CCD camera; 610, second CCD camera; 611, adjustment knob; 7, light transmission device; 71, optical switch; 72, second femtosecond reflector; 73, third aperture; 74, incident window; 8, optical fiber; 81, optical channel; 82, air inlet; 83, air outlet ; 9, moving device; 91, fixed base; 92, moving platform; 93, tension spring; 94, limit rod; 95, rotating block; 96, ionization platform; 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; 11 2. Intake main 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 reflector; 132. First adjustment knob; 133. First filter glass; 134. Second filter glass; 135. Second adjustment knob; 136. Third adjustment knob; 137. First observation window; 138. Second observation window. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] See also Figure 1-Figure 3As shown, the present invention is an extreme ultraviolet light generator, comprising: an extreme ultraviolet light generating cabin 2, on the side wall of which an inspection cabin 3 and a light source processing cabin 4 are suspended. The bottom of the inspection cabin 3 and the bottom of the light source processing cabin 4 are suspended on the two side walls of the extreme ultraviolet light generating cabin 2 through connecting parts, so that the top cover of the inspection cabin 3 and the top cover of the light source processing cabin 4 are both located on the side of the entire extreme ultraviolet light generator. Three connecting parts are provided on each side wall, and the installation is performed in a manner of determining a plane with three points, which reduces the difficulty and requirements for the processing of the outer surface of the cabin in the early stage, and the hanging installation can also reasonably utilize the space of the equipment. A shell 1 is provided on the outside of the extreme ultraviolet light generating cabin 2, and the inspection cabin 3 and the light source processing cabin 4 are both located inside the shell 1, and the three cabins are fixed in the shell 1.

[0055] See also Figure 7-Figure 8 As shown, a plurality of mutually independent cavities are arranged in the extreme ultraviolet light generating chamber 2, and the cavities include a normal pressure cavity 21, a vacuum cavity 22 is arranged on one side of the normal pressure cavity 21, and an observation window is also arranged on the top cover of the vacuum cavity 22 to facilitate observation of the extreme ultraviolet light generation inside. A transmission cavity 23 and an air path cavity 24 located below the transmission cavity 23 are arranged on one side of the vacuum cavity 22, and a light outlet 27 is provided in the transmission cavity 23.

[0056] Among them, see Fig. 9 , Fig.11 , Figure 18-19 As shown, the vacuum cavity 22 and the transmission cavity 23 are both configured to be a vacuum environment adapted to the propagation of extreme ultraviolet light. The vacuum cavity 22 and the transmission cavity 23 are connected via a differential system 12, which 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 10Pa, and the air pressure in the transmission cavity 23 is -4Pa. 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.

[0057] Specifically, the differential system 12 is provided with a first channel 121 with a gradually increasing inner diameter and a second channel 122 with a uniform inner diameter. The first channel 121 is arranged in the vacuum cavity 22, the second channel 122 is arranged in the transmission cavity 23, and the first channel 121 and the second channel 122 are arranged coaxially. 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, and the two holes determine a straight line, which can ensure that the extreme ultraviolet light can pass through the differential system 12 and enter the transmission cavity 23 while allowing the reaction gas to pass. In addition, the first channel 121 is set as a tapered channel with a gradually increasing inner diameter, which can avoid the angle deviation of the differential system 12 during installation, which causes the extreme ultraviolet light path to be unable to pass.

[0058] See also Figure 4 , Figure 7As shown, the inspection cabin 3 is provided with a collimator 5, and the collimator 5 is used to inject the inspection light into the optical fiber 8. The collimator 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. The output end of the laser pen 51 is respectively provided with a first aperture 52, a first silver-plated reflector 53, a second silver-plated reflector 54, and a third silver-plated reflector 55 along the transmission direction of the inspection light. After the green light passes through the first aperture 52, it is reflected by the first silver-plated reflector 53, the second silver-plated reflector 54, and the third silver-plated reflector 55, and then it is injected into the normal pressure cavity 21 from the third light hole 31 opened in the inspection cabin 3 and the second light hole 29 opened in the extreme ultraviolet light generating cabin 2.

[0059] See also Figure 7-10 As shown, the extreme ultraviolet light generating chamber 2 is provided with a light passing device 7 and a moving device 9 for adjusting the position of the optical fiber 8. The light passing device 7 is located in the atmospheric pressure cavity 21, and the light passing device 7 includes an optical switch 71, a second femtosecond reflector 72 is provided on one side of the optical switch 71, and the second femtosecond reflector 72 is provided with a third aperture 73 and an incident window 74 along the green light transmission direction, and the window sheet on the incident window 74 is coated with an infrared anti-reflection film.

[0060] When the collimation device 5 is in operation, the second femtosecond reflector 72 needs to be removed (the second femtosecond reflector 72 is fixed in the atmospheric pressure cavity 21 by bolts, and 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 aperture 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 is emitted from the light outlet 27. A baffle is placed at the light outlet 27. The appearance of a green light spot on the baffle proves that the position of the optical fiber 8 is accurate, and the subsequent generation operation of extreme ultraviolet light can be performed. If the green light spot does not appear on the baffle, the position of the optical fiber 8 needs to be collimated or corrected.

[0061] See also Figure 7-Figure 12 As shown, the collimating device 5 cooperates with the moving device 9 to collimate the optical fiber 8 through the inspection light.

[0062] Specifically, the mobile device 9 includes a fixed base 91, which is fixedly mounted on the vacuum chamber 22, and a mobile platform 92 is also arranged above the fixed base 91. The fixed base 91 is rotatably connected to a rotating block 95 through a bearing, and a limit rod 94 is arranged above the rotating block 95, and the limit rod 94 is fixedly mounted on the mobile platform 92. An ionization platform 96 is arranged in the mobile platform 92, and the ionization platform 96 is connected to an optical fiber rack to which an optical fiber 8 is fixed. The extreme ultraviolet light generating chamber 2 is connected to a first adjusting screw 99 and a second adjusting screw 910, and the first adjusting screw 99 is used to drive the rotating block 95 to rotate, and the second adjusting screw 910 is used to drive the ionization platform 96 to move on the mobile platform 92.

[0063] In this embodiment, when the position of the optical fiber 8 is aligned or corrected, the two first adjustment screws 99 are rotated 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, and the limit rod 94 drives the moving platform 92 to move upward. At this time, under the action of the front and rear limit rods 94, the moving platform 92 swings on the yz plane until the optical fiber 8 and the central axis of the incident window 74 are located in the same plane (i.e., the xy plane). Then the two second adjustment screws 910 are rotated to move the end of the second adjustment screw 910 toward the ionization stage 96. Under the action of the second adjustment screw 910, the ionization stage 96 twists on the xy plane until the optical fiber 8 is coaxial with the incident window 74, so that the subsequent red laser beam passing through the incident window 74 can remain coaxial with the optical fiber 8, which is conducive to the generation of extreme ultraviolet light. 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, so that the green light emitted by the laser pen 51 passes through the optical fiber 8 and the differential system 12, is emitted from the light outlet 27, and forms a light spot on the baffle at the light outlet 27.

[0064] It should be noted that a fixing rod 97 is fixed to the top of the movable platform 92 by bolts, and a pressure strip 98 is arranged between the fixing rod 97 and the ionization platform 96. The pressure strip 98 presses the ionization platform 96 at the bottom downward, so that the ionization platform 96 can be lifted and lowered together with the movable platform 92 during the lifting process.

[0065] It is understandable that a plurality of tension springs 93 are provided at the bottom of the mobile platform 92, and the tension springs 93 are used to pull the mobile platform 92 in the direction of the fixed base 91. The second adjusting screw 910 is connected to the mobile platform 92 through a threaded sleeve, and the threaded sleeve is fixedly installed on the mobile platform 92. A plurality of tension springs 93 are also provided on one side of the ionization platform 96, and the tension spring 93 here can eliminate the matching clearance between the second adjusting screw 910 and the threaded sleeve, so that the adjustment accuracy of the second adjusting screw 910 is higher. When the ionization platform 96 needs to be reset or adjusted, the first adjusting screw 99 and the second adjusting screw 910 are rotated in the opposite direction. Under the pulling action of the tension spring 93, the ionization platform 96 always moves in the xy plane in close contact with the second adjusting screw 910, and the ionization platform 96 always moves in the yz plane in close contact with the mobile platform 92, so that the vacuum chamber 22 can realize the reset or adjustment of the ionization platform 96 without breaking the vacuum environment.

[0066] In addition, three bull's eye bearings 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 platform 92, and the bull's eye bearings are fixed to the fixed base 91. When the fixed base 91 and the moving platform 92 are assembled, the bull's eye bearings are used for rough positioning by determining a plane through three points, and then the moving platform 92 is fine-tuned with three top screws (not shown in the figure) to keep the side wall of the fixed base 91 parallel to the side wall of the moving platform 92. Correspondingly, three bull's eye bearings are also arranged between the bottom of the inner surface of the moving platform 92 and the bottom of the outer surface of the ionization platform 96, and the bull's eye bearings are fixed to the moving platform 92. The bull's eye bearings here can not only be used for positioning, but also can reduce the friction between the ionization platform 96 and the moving platform 92 when it moves. This is because if the ionization platform 96 and the moving platform 92 are in surface contact, the contact area is large, resulting in greater friction, and the bull's eye bearings can change the ionization platform 96 from surface contact to point contact, and the three-point contact method can effectively reduce friction, thereby increasing the service life of the ionization platform 96.

[0067] See also Figure 3 , Figure 5-Figure 6 , Figure 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 electrically controlled femtosecond reflector 61, and a second aperture 62, a half-wave plate 63, a convex lens 64, and a second electrically controlled femtosecond reflector 65 are sequentially arranged in front of the first electrically controlled femtosecond reflector 61 along the long side direction of the light source processing chamber 4. The convex lens 64 is connected to the moving seat, and the moving seat is connected to the lead screw. An adjustment knob 611 is arranged at one end of the lead screw. By rotating the adjustment knob 611, the moving seat can be moved, and then the position of the convex lens 64 can be adjusted to focus the red laser beam.

[0068] Furthermore, a first femtosecond reflector 66, a wedge-shaped prism 67, and a fourth silver-coated reflector 68 are sequentially arranged on one side of the second electrically controlled femtosecond reflector 65 along the short side of the light source processing chamber 4. A first CCD camera 69 is arranged on one side of the wedge-shaped prism 67 along the long side of the light source processing chamber 4, and a second CCD camera 610 is arranged on one side of the fourth silver-coated reflector 68.

[0069] The reflection angles of the first electrically controlled femtosecond reflector 61 and the second electrically controlled femtosecond reflector 65 are adjusted by comparing the pixel points where the light spot in the first CCD camera 69 is located with the pixel points where the light spot in the second CCD camera 610 is located. 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 electrically controlled femtosecond reflector 61, passes through the second aperture 62, the half-wave plate 63, and the convex lens 64, and is then reflected by the second electrically controlled femtosecond reflector 65 and the first femtosecond reflector 66, and is emitted 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 emitted from the fourth light hole 42 enters the optical switch 71 through the first light hole 28, is then reflected by the second femtosecond reflector 72, enters the optical fiber 8 through the third aperture 73 and the incident window 74, and finally irradiates the baffle at the light outlet 27 through the differential system 12 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 minimized, 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 the loss. 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 part of the light energy to fail to be effectively coupled into the optical fiber 8. 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 and reduces reflection and loss.

[0070] The first femtosecond reflector 66 transmits a portion of the red laser beam, which as a transmitted beam enters the wedge-shaped prism 67, and a portion of the transmitted beam is reflected by the wedge-shaped prism 67 to the first CCD camera 69, and another portion of the transmitted beam passes through the wedge-shaped prism 67 and is reflected by the fourth silver-plated reflector 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, and 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 in the two cameras are located are in 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 in the two cameras are located are in different positions, it is necessary to adjust the reflection angles of the first electrically-controlled femtosecond reflector 61 and the second electrically-controlled femtosecond reflector 65.

[0071] See also Figure 7-Figure 17As shown, a gas circuit system 11 is arranged in the extreme ultraviolet light generating chamber 2, and the gas circuit system 11 is used to provide reaction gas to the optical fiber 8. The gas circuit system 11 includes an air inlet pipeline 111, and the input end of the air inlet pipeline 111 is connected to an external gas source, and the gas source introduces reaction gas into the air inlet pipeline 111. According to the required band of extreme ultraviolet light, the corresponding reaction gas is selected, and the reaction gas includes but is not limited to argon and helium. In the present application, the reaction gas is argon. An air inlet main valve 112 and a flow regulator 113 are arranged along the air flow direction of the air inlet pipeline 111, and a three-way valve 114 is arranged at the end of the air inlet pipeline 111. The three-way valve 114 connects two branch pipes, and the two branch pipes are respectively a first branch pipe 115 and a second branch pipe 116. The output end of the first branch pipe 115 is located in the vacuum chamber 22, and the second branch pipe 116 is connected to the ionization table 96.

[0072] The ionization platform 96 is provided with a water inlet channel 961 and a water outlet channel 962, and the ionization platform 96 is provided with an air inlet channel 963, which is not connected to the water inlet channel 961 and the water outlet channel 962. The optical fiber rack fixed on the ionization platform 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, and the optical channel 81 is provided with an air inlet hole 82 downwardly, and the optical channel 81 is provided with an air outlet hole 83 upwardly, and the air inlet hole 82 is connected to the air outlet channel 964.

[0073] In this embodiment, the focusing device 6 cooperates with the gas path system 11 to make the red laser beam injected into the vacuum cavity 22 ionize with the reaction gas in the optical fiber 8 to generate extreme ultraviolet light. Specifically, the main air inlet 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, and 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, and 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, and the generated extreme ultraviolet light enters the transmission cavity 23 through the differential system 12. The reaction gas is continuously filled into the ionization stage 96, and the gas in the optical fiber 8 is continuously output to the vacuum cavity 22 from the optical channel 81 and the air outlet 83. In order to ensure the vacuum degree of the vacuum cavity 22 and the transmission cavity 23, it is necessary to connect the vacuum pump 118 at the first air pumping port 25 and the second air pumping port 26 to continuously evacuate.

[0074] It is understandable 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 before introducing new gas. When changing the air, close the main air inlet valve 112. Due to the small inner diameters of the optical channel 81, the air inlet hole 82 and the air outlet hole 83, it is difficult to quickly exhaust the reaction gas retained in the air inlet pipe 111 and the second branch pipe 116. At this time, it is necessary to open the control valve 117, and set a first branch pipe 115 connected to the vacuum chamber 22. When the vacuum pump 118 is evacuated, the reaction gas in the air inlet pipe 111 and the second branch pipe 116 can be directly introduced into the first branch pipe 115. 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.

[0075] Since the temperature of the ionization platform 96 will rise when the extreme ultraviolet light is generated, the ionization platform 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 → 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 water inlet pipeline 101 and the water outlet pipeline 102 are made of stainless steel bellows in the pipeline part located in the vacuum chamber 22. The stainless steel pipe can not only adapt to the vacuum environment to avoid deformation of the pipeline due to pressure difference, but also adapt to the movement of the ionization platform 96. In the vacuum chamber 22, the interfaces of the return pipe 104, the water inlet pipe 101, and the water outlet pipe 102 are all connected to the corresponding components by using stainless steel quick-connect joints and sealing rings to prevent the cooling water from gasifying 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, and the probe of the thermocouple 103 extends into the vacuum chamber 22 and cooperates with the temperature sensor provided on the ionization table 96. When the temperature of the ionization table 96 is higher than the threshold, the optical switch 71 is closed, and the red laser beam cannot enter the optical fiber 8 at this time, which plays a role of overheating protection.

[0076] See also Figure 1-Figure 3 , Fig. 20As shown, the extreme ultraviolet light generating chamber 2 is connected to the slit adjustment device 13, and the slit adjustment device 13 includes two filter glasses arranged up and down in the transmission cavity 23, namely the first filter glass 133 and the second filter glass 134, and both filter glasses are silver-plated reflectors. The first filter glass 133 and the second filter glass 134 are both arranged at the light outlet 27. The gap between the first filter glass 133 and the second filter glass 134 serves as a slit for passing the extreme ultraviolet light, and the positions of the first filter glass 133 and the second filter glass 134 are moved to adjust the slit to filter stray light in the extreme ultraviolet light.

[0077] Specifically, the first filter glass 133 is connected to the second adjustment knob 135 through a screw structure, and correspondingly, the second filter glass 134 is also connected to the third adjustment knob 136 through a screw structure. The height of the first filter glass 133 can be adjusted by turning the second adjustment knob 135, and the height of the second filter glass 134 can be adjusted by turning the third adjustment knob 136. A third femtosecond reflector 131 is arranged on one side of the two filter glasses, and the third femtosecond reflector 131 is connected to the first adjustment knob 132 through a rotating shaft, and the rotating shaft is installed on the wall of the extreme ultraviolet light generating cabin 2 through a bearing seat, and the third femtosecond reflector 131 can be rotated by turning the first adjustment knob 132.

[0078] In this embodiment, 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 luminous flux can be connected to the first observation window 137 to detect the luminous flux of the extreme ultraviolet light. The luminous flux mainly measures the transmittance of light. The efficiency of the red laser beam in generating extreme ultraviolet light is measured 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. After the detection, the first adjustment knob 132 is turned again 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. Some stray light will be mixed in the process of generating extreme ultraviolet light. Since the stray light and the extreme ultraviolet light have different wavelengths, the slit is adjusted to a width that matches the wavelength 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, thereby improving the purity of the extreme ultraviolet light.

[0079] The first electrically controlled femtosecond reflector 61, the second electrically controlled femtosecond reflector 65, the first femtosecond reflector 66, the second femtosecond reflector 72, and the third femtosecond reflector 131 are generally referred to as ultrafast reflectors in the conventional terminology of those skilled in the art. Ultrafast reflectors are used to process ultrashort pulse light (in optics, an ultrashort pulse of light refers to a pulse with a duration of less than 10 femtoseconds) in a short time. -15Ultrafast mirrors are designed to be able to withstand large laser powers and efficiently reflect and control light waves on a short time scale.

[0080] In the present 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 coordination between the various devices during the integration process are overcome, so that the entire extreme ultraviolet light generator is more integrated and smaller in size, which is conducive to experimental operation and carrying.

[0081] See also Fig.21 As shown, in another embodiment, a method of using an extreme ultraviolet light generator includes:

[0082] The collimating device 5 is running, 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 set at the light outlet 27 presents a light spot, and the collimation of the optical fiber 8 is completed.

[0083] The collimating device 5 is closed, and the light source processing chamber 4 receives the red laser beam emitted by the external light source. The red laser beam is adjusted in optical path and focused by the focusing device 6 and then emitted into the optical fiber 8.

[0084] The vacuum chamber 22 and the transmission chamber 23 are continuously evacuated, the gas circuit system 11 and the cooling system 10 are in operation, and the optical fiber 8 continuously receives the reaction gas transported by the gas circuit system 11, and the red laser beam and the reaction gas are ionized to generate extreme ultraviolet light. It should be noted that the reaction gas can be transported to the optical fiber 8 before the external light source emits the red laser beam, or the red laser beam can be emitted first and then the reaction gas is introduced, as long as the optical fiber 8 is filled with the reaction gas and there is also a red laser beam, ionization can be performed to generate extreme ultraviolet light.

[0085] The extreme ultraviolet light generated in the optical fiber 8 is emitted toward the light outlet 27 , and 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.

[0086] The specific steps are as follows:

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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 electrically controlled femtosecond reflector 61, passes through the second aperture 62, the half-wave plate 63, and the convex lens 64, and is then reflected by the second electrically controlled femtosecond reflector 65 and the first femtosecond reflector 66, and is emitted from the fourth light hole 42 opened in the light source processing chamber 4. Turn on the optical switch 71, the red laser beam emitted from the fourth light hole 42 enters the optical switch 71 through the first light hole 28, is reflected by the second femtosecond reflector 72, enters the optical fiber 8 through the third aperture 73 and the incident window 74, and finally irradiates the baffle at the light outlet 27 through the differential system 12 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.

[0092] 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 reflector 66 transmits a portion of the red laser beam, this portion of the red laser beam will enter the wedge prism 67 as a transmitted light beam, and a portion of the transmitted light beam is reflected by the wedge prism 67 to the first CCD camera 69, and the other portion of the transmitted light beam passes through the wedge prism 67 and is reflected by the fourth silver-plated reflector 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, and 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 in the two cameras are located are at the same grid 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 in the two cameras are located are at different grid positions, the optical path of the red laser beam needs to be adjusted.

[0093] The method of adjusting the optical path of the red laser beam is as follows: preset a standard pixel point, compare the pixel point where the light spot in the first CCD camera 69 is located with the pixel point where the light spot in the second CCD camera 610 is located, and adjust the reflection angles of the first electrically-controlled femtosecond reflector 61 and the second electrically-controlled femtosecond reflector 65 so that the pixel points where the two light spots are located are located at the standard pixel points, and the two points determine a straight line. When the pixel points where the two light spots are located are consistent, the red laser beam emitted into the optical fiber 8 is coaxial with the optical fiber 8.

[0094] S3, the vacuum chamber 22 and the transmission chamber 23 are continuously evacuated, the gas system 11 and the cooling system 10 are running, the optical fiber 8 continuously receives the argon gas transported by the gas system 11, and the red laser beam and the reaction gas are ionized to generate extreme ultraviolet light.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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 .

[0100] 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 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) for injecting a red laser beam into the optical fiber (8); the extreme ultraviolet light generating chamber (2) is provided with a gas path system (11) for supplying 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.

2. The extreme ultraviolet light generator according to claim 1, 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), and the transmission cavity (23) is provided with a light outlet (27).

3. The extreme ultraviolet light generator according to claim 1, characterized in that: The extreme ultraviolet light generating chamber (2) is connected to a slit adjusting device (13), wherein the slit adjusting device (13) is provided with a slit with adjustable width, and the slit is used to filter stray light in the extreme ultraviolet light.

4. The extreme ultraviolet light generator according to claim 1, 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.

5. The extreme ultraviolet light generator according to claim 2, characterized in that: The moving device (9) comprises a fixed base (91), the fixed base (91) is fixedly mounted on the vacuum chamber (22), a moving platform (92) that can swing on a yz plane is arranged above the fixed base (91), an ionization platform (96) that can twist on an xy plane is arranged inside the moving platform (92), and the ionization platform (96) is connected to an optical fiber rack on which the optical fiber (8) is fixed.

6. The extreme ultraviolet light generator according to claim 5, 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 direction of the fixed base (91).

7. The extreme ultraviolet light generator according to claim 5, characterized in that: The movable platform (92) is provided with a threaded sleeve, and a plurality of tension springs (93) are also provided on one side of the ionization platform (96). The tension springs (93) are used to eliminate the matching clearance generated by the threaded sleeve during operation.

8. The extreme ultraviolet light generator according to claim 5, characterized in that: The optical fiber (8) defines an optical channel (81), the optical channel (81) defines an air inlet (82) downward, the optical channel (81) defines an air outlet (83) upward, and the air inlet (82) is connected to the ionization table (96).

9. The extreme ultraviolet light generator according to claim 2, 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.

10. A method for using the extreme ultraviolet light generator according to any one of claims 1 to 9, characterized in that: include: The collimating device (5) is in operation, and the green light emitted by it is used as the inspection light. The position of the optical fiber (8) is adjusted by the moving device (9) until the inspection light is coaxial with the optical fiber (8), and the baffle plate arranged at the light outlet (27) presents a light spot, and the optical fiber (8) is collimated; The collimating device (5) is closed, and the light source processing chamber (4) receives the red laser beam emitted by the external light source. The red laser beam is adjusted in optical path and focused by the focusing device (6) before being emitted into the optical fiber (8); The vacuum chamber (22) and the transmission chamber (23) are continuously evacuated, the gas circuit system (11) and the cooling system (10) are in operation, the optical fiber (8) continuously receives the reaction gas transported by the gas circuit system (11), and the red laser beam is ionized with the reaction gas to generate extreme ultraviolet light; 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.

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